Module:Citation/CS1: Difference between revisions

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    ---------------------------------------------------------------------
    -- Module:Citation/CS1 - Lua module for Citation Style 1 templates
    ---------------------------------------------------------------------
    --                              (see NOTES at bottom)
    --require "mw.text"


    local z = {
    require('Module:No globals');
        wikitext = require("Module:Wikitext"),
        mw = require("Module:Mw")
    }


    function hideinprint(content)
    --[[--------------------------< F O R W A R D  D E C L A R A T I O N S >--------------------------------------
        return content
    each of these counts against the Lua upvalue limit
    ]]
     
    local validation; -- functions in Module:Citation/CS1/Date_validation
     
    local utilities; -- functions in Module:Citation/CS1/Utilities
    local z ={}; -- table of tables in Module:Citation/CS1/Utilities
     
    local identifiers; -- functions and tables in Module:Citation/CS1/Identifiers
    local metadata; -- functions in Module:Citation/CS1/COinS
    local cfg = {}; -- table of configuration tables that are defined in Module:Citation/CS1/Configuration
    local whitelist = {}; -- table of tables listing valid template parameter names; defined in Module:Citation/CS1/Whitelist
     
    --[[------------------< P A G E  S C O P E  V A R I A B L E S >---------------
    declare variables here that have page-wide scope that are not brought in from
    other modules; that are created here and used here
    ]]
    local added_deprecated_cat; -- Boolean flag so that the category is added only once
    local added_discouraged_cat; -- Boolean flag so that the category is added only once
    local added_vanc_errs; -- Boolean flag so we only emit one Vancouver error / category
    local Frame; -- holds the module's frame table
     
    --[[--------------------------< F I R S T _ S E T >------------------------------------------------------------
     
    Locates and returns the first set value in a table of values where the order established in the table,
    left-to-right (or top-to-bottom), is the order in which the values are evaluated.  Returns nil if none are set.
     
    This version replaces the original 'for _, val in pairs do' and a similar version that used ipairs.  With the pairs
    version the order of evaluation could not be guaranteed.  With the ipairs version, a nil value would terminate
    the for-loop before it reached the actual end of the list.
     
    ]]
     
    local function first_set (list, count)
    local i = 1;
    while i <= count do -- loop through all items in list
    if utilities.is_set( list[i] ) then
    return list[i]; -- return the first set list member
    end
    i = i + 1; -- point to next
    end
    end
    end


    function onlyinprint(content)
     
        return ""
    --[[--------------------------< A D D _ V A N C _ E R R O R >----------------------------------------------------
     
    Adds a single Vancouver system error message to the template's output regardless of how many error actually exist.
    To prevent duplication, added_vanc_errs is nil until an error message is emitted.
     
    added_vanc_errs is a Boolean declared in page scope variables above
     
    ]]
     
    local function add_vanc_error (source, position)
    if added_vanc_errs then return end
    added_vanc_errs = true; -- note that we've added this category
    table.insert( z.message_tail, { utilities.set_message ( 'err_vancouver', {source, position}, true ) } );
    end
     
     
    --[[--------------------------< I S _ S C H E M E >------------------------------------------------------------
     
    does this thing that purports to be a URI scheme seem to be a valid scheme?  The scheme is checked to see if it
    is in agreement with http://tools.ietf.org/html/std66#section-3.1 which says:
    Scheme names consist of a sequence of characters beginning with a
      letter and followed by any combination of letters, digits, plus
      ("+"), period ("."), or hyphen ("-").
     
    returns true if it does, else false
     
    ]]
     
    local function is_scheme (scheme)
    return scheme and scheme:match ('^%a[%a%d%+%.%-]*:'); -- true if scheme is set and matches the pattern
    end
    end


    function nowiki(frame, content)
     
        return z.mw.text.tag({name="nowiki",contents=content,params={}}, frame)
    --[=[-------------------------< I S _ D O M A I N _ N A M E >--------------------------------------------------
     
    Does this thing that purports to be a domain name seem to be a valid domain name?
     
    Syntax defined here: http://tools.ietf.org/html/rfc1034#section-3.5
    BNF defined here: https://tools.ietf.org/html/rfc4234
    Single character names are generally reserved; see https://tools.ietf.org/html/draft-ietf-dnsind-iana-dns-01#page-15;
    see also [[Single-letter second-level domain]]
    list of TLDs: https://www.iana.org/domains/root/db
     
    RFC 952 (modified by RFC 1123) requires the first and last character of a hostname to be a letter or a digit.  Between
    the first and last characters the name may use letters, digits, and the hyphen.
     
    Also allowed are IPv4 addresses. IPv6 not supported
     
    domain is expected to be stripped of any path so that the last character in the last character of the TLD.  tld
    is two or more alpha characters.  Any preceding '//' (from splitting a URL with a scheme) will be stripped
    here.  Perhaps not necessary but retained in case it is necessary for IPv4 dot decimal.
     
    There are several tests:
    the first character of the whole domain name including subdomains must be a letter or a digit
    internationalized domain name (ASCII characters with .xn-- ASCII Compatible Encoding (ACE) prefix xn-- in the TLD) see https://tools.ietf.org/html/rfc3490
    single-letter/digit second-level domains in the .org, .cash, and .today TLDs
    q, x, and z SL domains in the .com TLD
    i and q SL domains in the .net TLD
    single-letter SL domains in the ccTLDs (where the ccTLD is two letters)
    two-character SL domains in gTLDs (where the gTLD is two or more letters)
    three-plus-character SL domains in gTLDs (where the gTLD is two or more letters)
    IPv4 dot-decimal address format; TLD not allowed
     
    returns true if domain appears to be a proper name and TLD or IPv4 address, else false
     
    ]=]
     
    local function is_domain_name (domain)
    if not domain then
    return false; -- if not set, abandon
    end
    domain = domain:gsub ('^//', ''); -- strip '//' from domain name if present; done here so we only have to do it once
    if not domain:match ('^[%w]') then -- first character must be letter or digit
    return false;
    end
     
    if domain:match ('^%a+:') then -- hack to detect things that look like s:Page:Title where Page: is namespace at Wikisource
    return false;
    end
     
    local patterns = { -- patterns that look like URLs
    '%f[%w][%w][%w%-]+[%w]%.%a%a+$', -- three or more character hostname.hostname or hostname.tld
    '%f[%w][%w][%w%-]+[%w]%.xn%-%-[%w]+$', -- internationalized domain name with ACE prefix
    '%f[%a][qxz]%.com$', -- assigned one character .com hostname (x.com times out 2015-12-10)
    '%f[%a][iq]%.net$', -- assigned one character .net hostname (q.net registered but not active 2015-12-10)
    '%f[%w][%w]%.%a%a$', -- one character hostname and ccTLD (2 chars)
    '%f[%w][%w][%w]%.%a%a+$', -- two character hostname and TLD
    '^%d%d?%d?%.%d%d?%d?%.%d%d?%d?%.%d%d?%d?', -- IPv4 address
    }
     
    for _, pattern in ipairs (patterns) do -- loop through the patterns list
    if domain:match (pattern) then
    return true; -- if a match then we think that this thing that purports to be a URL is a URL
    end
    end
     
    for _, d in ipairs ({'cash', 'company', 'today', 'org'}) do -- look for single letter second level domain names for these top level domains
    if domain:match ('%f[%w][%w]%.' .. d) then
    return true
    end
    end
    return false; -- no matches, we don't know what this thing is
    end
    end


    function externallinkid(frame, args)
     
        local sep = args.separator or "&nbsp;"
    --[[--------------------------< I S _ U R L >------------------------------------------------------------------
        args.suffix = args.suffix or ""
     
        local url_string = args.id
    returns true if the scheme and domain parts of a URL appear to be a valid URL; else false.
        if args.encode == true or args.encode == nil then
     
            url_string = z.mw.url.encode( url_string );
    This function is the last step in the validation process. This function is separate because there are cases that
        end
    are not covered by split_url(), for example is_parameter_ext_wikilink() which is looking for bracketted external
       
    wikilinks.
        local t0 = onlyinprint(args.label .. sep .. args.id)
     
        local t1 = hideinprint("[[" .. args.link .. "|" .. args.label .. "]]" .. sep .. "[" .. args.prefix .. url_string .. args.suffix .. " " .. nowiki(frame, args.id) .. "]")
    ]]
       
     
        return t0 .. t1
    local function is_url (scheme, domain)
    if utilities.is_set (scheme) then -- if scheme is set check it and domain
    return is_scheme (scheme) and is_domain_name (domain);
    else
    return is_domain_name (domain); -- scheme not set when URL is protocol-relative
    end
    end
    end


    function internallinkid(frame, args)
     
        local sep = args.separator or "&nbsp;"
    --[[--------------------------< S P L I T _ U R L >------------------------------------------------------------
        args.suffix = args.suffix or ""
     
        local t0 = onlyinprint(args.label .. sep .. args.id)
    Split a URL into a scheme, authority indicator, and domain.
        local t1 = hideinprint("[[" .. args.link .. "|" .. args.label .. "]]" .. sep .. "[[" .. args.prefix .. args.id .. args.suffix .. "|" .. nowiki(frame, args.id) .. "]]")
     
        return t0 .. t1
    First remove Fully Qualified Domain Name terminator (a dot following TLD) (if any) and any path(/), query(?) or fragment(#).
     
    If protocol-relative URL, return nil scheme and domain else return nil for both scheme and domain.
     
    When not protocol-relative, get scheme, authority indicator, and domain.  If there is an authority indicator (one
    or more '/' characters immediately following the scheme's colon), make sure that there are only 2.
     
    Any URL that does not have news: scheme must have authority indicator (//).  TODO: are there other common schemes
    like news: that don't use authority indicator?
     
    Strip off any port and path;
     
    ]]
     
    local function split_url (url_str)
    local scheme, authority, domain;
    url_str = url_str:gsub ('([%a%d])%.?[/%?#].*$', '%1'); -- strip FQDN terminator and path(/), query(?), fragment (#) (the capture prevents false replacement of '//')
     
    if url_str:match ('^//%S*') then -- if there is what appears to be a protocol-relative URL
    domain = url_str:match ('^//(%S*)')
    elseif url_str:match ('%S-:/*%S+') then -- if there is what appears to be a scheme, optional authority indicator, and domain name
    scheme, authority, domain = url_str:match ('(%S-:)(/*)(%S+)'); -- extract the scheme, authority indicator, and domain portions
    if utilities.is_set (authority) then
    authority = authority:gsub ('//', '', 1); -- replace place 1 pair of '/' with nothing;
    if utilities.is_set(authority) then -- if anything left (1 or 3+ '/' where authority should be) then
    return scheme; -- return scheme only making domain nil which will cause an error message
    end
    else
    if not scheme:match ('^news:') then -- except for news:..., MediaWiki won't link URLs that do not have authority indicator; TODO: a better way to do this test?
    return scheme; -- return scheme only making domain nil which will cause an error message
    end
    end
    domain = domain:gsub ('(%a):%d+', '%1'); -- strip port number if present
    end
    return scheme, domain;
    end
     
     
    --[[--------------------------< L I N K _ P A R A M _ O K >---------------------------------------------------
     
    checks the content of |title-link=, |series-link=, |author-link=, etc. for properly formatted content: no wikilinks, no URLs
     
    Link parameters are to hold the title of a Wikipedia article, so none of the WP:TITLESPECIALCHARACTERS are allowed:
    # < > [ ] | { } _
    except the underscore which is used as a space in wiki URLs and # which is used for section links
     
    returns false when the value contains any of these characters.
     
    When there are no illegal characters, this function returns TRUE if value DOES NOT appear to be a valid URL (the
    |<param>-link= parameter is ok); else false when value appears to be a valid URL (the |<param>-link= parameter is NOT ok).
     
    ]]
     
    local function link_param_ok (value)
    local scheme, domain;
    if value:find ('[<>%[%]|{}]') then -- if any prohibited characters
    return false;
    end
     
    scheme, domain = split_url (value); -- get scheme or nil and domain or nil from URL;
    return not is_url (scheme, domain); -- return true if value DOES NOT appear to be a valid URL
    end
     
     
    --[[--------------------------< L I N K _ T I T L E _ O K >---------------------------------------------------
     
    Use link_param_ok() to validate |<param>-link= value and its matching |<title>= value.
     
    |<title>= may be wiki-linked but not when |<param>-link= has a value. This function emits an error message when
    that condition exists
     
    check <link> for inter-language interwiki-link prefix. prefix must be a MediaWiki-recognized language
    code and must begin with a colon.
     
    ]]
     
    local function link_title_ok (link, lorig, title, torig)
    local orig;
    if utilities.is_set (link) then -- don't bother if <param>-link doesn't have a value
    if not link_param_ok (link) then -- check |<param>-link= markup
    orig = lorig; -- identify the failing link parameter
    elseif title:find ('%[%[') then -- check |title= for wikilink markup
    orig = torig; -- identify the failing |title= parameter
    elseif link:match ('^%a+:') then -- if the link is what looks like an interwiki
    local prefix = link:match ('^(%a+):'):lower(); -- get the interwiki prefix
     
    if cfg.inter_wiki_map[prefix] then -- if prefix is in the map, must have preceding colon
    orig = lorig; -- flag as error
    end
    end
    end
     
    if utilities.is_set (orig) then
    link = ''; -- unset
    table.insert( z.message_tail, { utilities.set_message ( 'err_bad_paramlink', orig)}); -- URL or wikilink in |title= with |title-link=;
    end
    return link; -- link if ok, empty string else
    end
     
     
    --[[--------------------------< C H E C K _ U R L >------------------------------------------------------------
     
    Determines whether a URL string appears to be valid.
     
    First we test for space characters. If any are found, return false. Then split the URL into scheme and domain
    portions, or for protocol-relative (//example.com) URLs, just the domain. Use is_url() to validate the two
    portions of the URL. If both are valid, or for protocol-relative if domain is valid, return true, else false.
     
    Because it is different from a standard URL, and because this module used external_link() to make external links
    that work for standard and news: links, we validate newsgroup names here. The specification for a newsgroup name
    is at https://tools.ietf.org/html/rfc5536#section-3.1.4
     
    ]]
     
    local function check_url( url_str )
    if nil == url_str:match ("^%S+$") then -- if there are any spaces in |url=value it can't be a proper URL
    return false;
    end
    local scheme, domain;
     
    scheme, domain = split_url (url_str); -- get scheme or nil and domain or nil from URL;
    if 'news:' == scheme then -- special case for newsgroups
    return domain:match('^[%a%d%+%-_]+%.[%a%d%+%-_%.]*[%a%d%+%-_]$');
    end
    return is_url (scheme, domain); -- return true if value appears to be a valid URL
    end
     
     
    --[=[-------------------------< I S _ P A R A M E T E R _ E X T _ W I K I L I N K >----------------------------
     
    Return true if a parameter value has a string that begins and ends with square brackets [ and ] and the first
    non-space characters following the opening bracket appear to be a URL.  The test will also find external wikilinks
    that use protocol-relative URLs. Also finds bare URLs.
     
    The frontier pattern prevents a match on interwiki-links which are similar to scheme:path URLs.  The tests that
    find bracketed URLs are required because the parameters that call this test (currently |title=, |chapter=, |work=,
    and |publisher=) may have wikilinks and there are articles or redirects like '//Hus' so, while uncommon, |title=[[//Hus]]
    is possible as might be [[en://Hus]].
     
    ]=]
     
    local function is_parameter_ext_wikilink (value)
    local scheme, domain;
     
    if value:match ('%f[%[]%[%a%S*:%S+.*%]') then -- if ext. wikilink with scheme and domain: [xxxx://yyyyy.zzz]
    scheme, domain = split_url (value:match ('%f[%[]%[(%a%S*:%S+).*%]'));
    elseif value:match ('%f[%[]%[//%S+.*%]') then -- if protocol-relative ext. wikilink: [//yyyyy.zzz]
    scheme, domain = split_url (value:match ('%f[%[]%[(//%S+).*%]'));
    elseif value:match ('%a%S*:%S+') then -- if bare URL with scheme; may have leading or trailing plain text
    scheme, domain = split_url (value:match ('(%a%S*:%S+)'));
    elseif value:match ('//%S+') then -- if protocol-relative bare URL: //yyyyy.zzz; may have leading or trailing plain text
    scheme, domain = split_url (value:match ('(//%S+)')); -- what is left should be the domain
    else
    return false; -- didn't find anything that is obviously a URL
    end
     
    return is_url (scheme, domain); -- return true if value appears to be a valid URL
    end
    end


    function amazon(frame, id, domain)
     
        if ( nil == domain ) then  
    --[[-------------------------< C H E C K _ F O R _ U R L >-----------------------------------------------------
            domain = "com"
     
        elseif ( "jp" == domain or "uk" == domain ) then
    loop through a list of parameters and their values.  Look at the value and if it has an external link, emit an error message.
            domain = "co." .. domain
     
        end
    ]]
        return externallinkid(frame, {link="Amazon Standard Identification Number",label="ASIN",prefix="//www.amazon."..domain.."/dp/",id=id})
     
    local function check_for_url (parameter_list)
    local error_message = '';
    for k, v in pairs (parameter_list) do -- for each parameter in the list
    if is_parameter_ext_wikilink (v) then -- look at the value; if there is a URL add an error message
    if utilities.is_set(error_message) then -- once we've added the first portion of the error message ...
    error_message = error_message .. ", "; -- ... add a comma space separator
    end
    error_message = error_message .. "&#124;" .. k .. "="; -- add the failed parameter
    end
    end
    if utilities.is_set (error_message) then -- done looping, if there is an error message, display it
    table.insert( z.message_tail, { utilities.set_message ( 'err_param_has_ext_link', {error_message}, true ) } );
    end
    end
    end


    function doi(frame, id, inactive, nocat)
        local cat = ""
        local text;
        if ( inactive ~= nil ) then
            text = "[[Digital object identifier|doi]]:" .. id;
            cat = cat .. "[[Category:Pages with DOIs inactive since " .. selectyear(inactive) .. "]]"
            inactive = " (inactive " .. inactive .. ")"
        else
            text = externallinkid(frame, {link="Digital object identifier",label="doi",prefix="http://dx.doi.org/",id=id,separator=":"})
            inactive = ""
        end
        if ( string.sub(id,1,3) ~= "10." ) then
            cat = cat .. "[[Category:Pages with DOI errors]]" .. '<span class="error"> Bad DOI (expected "10." prefix) in code number</span>'
        end
        if ( nocat and nocat ~= "" ) then cat = "" end
        return text .. inactive .. cat   
    end


    function url(frame, id)
    --[[--------------------------< S A F E _ F O R _ U R L >------------------------------------------------------
        local t0 = onlyinprint(id)
     
        local t1 = hideinprint("[" .. id .. " " .. nowiki(frame, id) .. "]")
    Escape sequences for content that will be used for URL descriptions
        return t0 .. t1
     
    ]]
     
    local function safe_for_url( str )
    if str:match( "%[%[.-%]%]" ) ~= nil then
    table.insert( z.message_tail, { utilities.set_message ( 'err_wikilink_in_url', {}, true ) } );
    end
    return str:gsub( '[%[%]\n]', {
    ['['] = '&#91;',
    [']'] = '&#93;',
    ['\n'] = ' ' } );
    end
    end


    function safeforurl( str )
     
        return str:gsub('%[','&#91;'):gsub('%]','&#93;'):gsub("\n", " ");
    --[[--------------------------< E X T E R N A L _ L I N K >----------------------------------------------------
     
    Format an external link with error checking
     
    ]]
     
    local function external_link( URL, label, source, access)
    local error_str = "";
    local domain;
    local path;
    local base_url;
     
    if not utilities.is_set ( label ) then
    label = URL;
    if utilities.is_set ( source ) then
    error_str = utilities.set_message ( 'err_bare_url_missing_title', { utilities.wrap_style ('parameter', source) }, false, " " );
    else
    error( cfg.messages["bare_url_no_origin"] );
    end
    end
    if not check_url( URL ) then
    error_str = utilities.set_message ( 'err_bad_url', {utilities.wrap_style ('parameter', source)}, false, " " ) .. error_str;
    end
    domain, path = URL:match ('^([/%.%-%+:%a%d]+)([/%?#].*)$'); -- split the URL into scheme plus domain and path
    if path then -- if there is a path portion
    path = path:gsub ('[%[%]]', {['['] = '%5b', [']'] = '%5d'}); -- replace '[' and ']' with their percent-encoded values
    URL = table.concat ({domain, path}); -- and reassemble
    end
     
    base_url = table.concat({ "[", URL, " ", safe_for_url (label), "]" }); -- assemble a wiki-markup URL
     
    if utilities.is_set (access) then -- access level (subscription, registration, limited)
    base_url = utilities.substitute (cfg.presentation['ext-link-access-signal'], {cfg.presentation[access].class, cfg.presentation[access].title, base_url}); -- add the appropriate icon
    end
    return table.concat ({base_url, error_str});
    end
    end


    function hyphentodash( str )
     
        return str:gsub( '-', '' );
    --[[--------------------------< D E P R E C A T E D _ P A R A M E T E R >--------------------------------------
     
    Categorize and emit an error message when the citation contains one or more deprecated parameters.  The function includes the
    offending parameter name to the error message.  Only one error message is emitted regardless of the number of deprecated
    parameters in the citation.
     
    added_deprecated_cat is a Boolean declared in page scope variables above
     
    ]]
     
    local function deprecated_parameter(name)
    if not added_deprecated_cat then
    added_deprecated_cat = true; -- note that we've added this category
    table.insert( z.message_tail, { utilities.set_message ( 'err_deprecated_params', {name}, true ) } ); -- add error message
    end
    end
    end


    function safeforitalics( str )
     
        if str == nil or str == '' then
    --[[--------------------------< D I S C O U R A G E D _ P A R A M E T E R >------------------------------------
            return str;
     
        else
    Categorize and emit an maintenance message when the citation contains one or more discouraged parameters.  Only
            if str:sub(1,1) == "'" then str = "<span />" .. str; end
    one error message is emitted regardless of the number of discouraged parameters in the citation.
            if str:sub(-1,-1) == "'" then str = str .. "<span />"; end
     
            return str;
    added_discouraged_cat is a Boolean declared in page scope variables above
        end
     
    ]]
     
    local function discouraged_parameter(name)
    if not added_discouraged_cat then
    added_discouraged_cat = true; -- note that we've added this category
    table.insert( z.message_tail, { utilities.set_message ( 'maint_discouraged', {name}, true ) } ); -- add maint message
    end
    end
    end


    function safejoin( tbl, duplicate_char )
        --[[
        Note: we use string functions here, rather than ustring functions.
       
        This has considerably faster performance and should work correctly as
        long as the duplicate_char is strict ASCII.  The strings
        in tbl may be ASCII or UTF8.
        ]]
       
        local str = '';
        local comp = '';
        for _, value in ipairs( tbl ) do
            if value == nil then value = ''; end
           
            if str == '' then
                str = value;
            elseif value ~= '' then
                if value:sub(1,1) == '<' then
                    -- Special case of values enclosed in spans and other markup.
                    comp = value:replace( "%b<>", "" );
                else
                    comp = value;
                end
               
                if comp:sub(1,1) == duplicate_char then
                    if str:sub(-1,-1) == duplicate_char then
                        str = str(1,-2) .. value;
                    elseif str:sub(-3,-1) == duplicate_char .. "''" then                 
                        str = str(1, -4) .. "''" .. value:sub(2);
                    elseif str:sub(-2,-1) == duplicate_char .. " " then
                        str = str:sub(1,-3) .. value;
                    else
                        str = str .. value;
                    end
                else
                    str = str .. value;
                end
            end
        end
        return str;
    end 


    function selectyear( str )
    --[=[-------------------------< K E R N _ Q U O T E S >--------------------------------------------------------
        local lang = mw.getContentLanguage();
     
        local good, result;
    Apply kerning to open the space between the quote mark provided by the module and a leading or trailing quote
        good, result = pcall( lang.formatDate, lang, 'Y', str )
    mark contained in a |title= or |chapter= parameter's value.
        if good then  
     
            return result;
    This function will positive kern either single or double quotes:
        else
    "'Unkerned title with leading and trailing single quote marks'"
            return '';
    " 'Kerned title with leading and trailing single quote marks' " (in real life the kerning isn't as wide as this example)
        end
    Double single quotes (italic or bold wiki-markup) are not kerned.
     
    Replaces Unicode quote marks in plain text or in the label portion of a [[L|D]] style wikilink with typewriter
    quote marks regardless of the need for kerning.  Unicode quote marks are not replaced in simple [[D]] wikilinks.
     
    Call this function for chapter titles, for website titles, etc.; not for book titles.
     
    ]=]
     
    local function kern_quotes (str)
    local cap = '';
    local cap2 = '';
    local wl_type, label, link;
     
    wl_type, label, link = utilities.is_wikilink (str); -- wl_type is: 0, no wl (text in label variable); 1, [[D]]; 2, [[L|D]]
    if 1 == wl_type then -- [[D]] simple wikilink with or without quote marks
    if mw.ustring.match (str, '%[%[[\"“”\'‘’].+[\"“”\'‘’]%]%]') then -- leading and trailing quote marks
    str = utilities.substitute (cfg.presentation['kern-wl-both'], str);
    elseif mw.ustring.match (str, '%[%[[\"“”\'‘’].+%]%]') then -- leading quote marks
    str = utilities.substitute (cfg.presentation['kern-wl-left'], str);
    elseif mw.ustring.match (str, '%[%[.+[\"“”\'‘’]%]%]') then -- trailing quote marks
    str = utilities.substitute (cfg.presentation['kern-wl-right'], str);
    end
     
    else -- plain text or [[L|D]]; text in label variable
    label = mw.ustring.gsub (label, '[“”]', '\"'); -- replace “” (U+201C & U+201D) with " (typewriter double quote mark)
    label = mw.ustring.gsub (label, '[‘’]', '\''); -- replace ‘’ (U+2018 & U+2019) with ' (typewriter single quote mark)
     
    cap, cap2 = mw.ustring.match (label, "^([\"\'])([^\'].+)"); -- match leading double or single quote but not doubled single quotes (italic markup)
    if utilities.is_set (cap) then
    label = utilities.substitute (cfg.presentation['kern-left'], {cap, cap2});
    end
    cap, cap2 = mw.ustring.match (label, "^(.+[^\'])([\"\'])$") -- match trailing double or single quote but not doubled single quotes (italic markup)
    if utilities.is_set (cap) then
    label = utilities.substitute (cfg.presentation['kern-right'], {cap, cap2});
    end
    if 2 == wl_type then
    str = utilities.make_wikilink (link, label); -- reassemble the wikilink
    else
    str = label;
    end
    end
    return str;
    end
    end


    function openlibrary(frame, id)
     
        local cat = ""
    --[[--------------------------< F O R M A T _ S C R I P T _ V A L U E >----------------------------------------
        local prefix = ""
     
        local code = id:sub(-1,-1)
    |script-title= holds title parameters that are not written in Latin-based scripts: Chinese, Japanese, Arabic, Hebrew, etc. These scripts should
        if ( code == "A" ) then
    not be italicized and may be written right-to-left.  The value supplied by |script-title= is concatenated onto Title after Title has been wrapped
            prefix = "http://openlibrary.org/authors/OL"
    in italic markup.
        elseif ( code == "M" ) then
     
            prefix = "http://openlibrary.org/books/OL"
    Regardless of language, all values provided by |script-title= are wrapped in <bdi>...</bdi> tags to isolate RTL languages from the English left to right.
        elseif ( code == "W" ) then
     
            prefix = "http://openlibrary.org/works/OL"
    |script-title= provides a unique feature.  The value in |script-title= may be prefixed with a two-character ISO 639-1 language code and a colon:
        else
    |script-title=ja:*** *** (where * represents a Japanese character)
            prefix = "http://openlibrary.org/OL"
    Spaces between the two-character code and the colon and the colon and the first script character are allowed:
            cat = cat .. "[[Category:Pages with OL errors]]"
    |script-title=ja : *** ***
        end
    |script-title=ja: *** ***
        local text = externallinkid(frame, {link="Open Library",label="OL",prefix=prefix,id=id})
    |script-title=ja :*** ***
        return text .. cat
    Spaces preceding the prefix are allowed: |script-title = ja:*** ***
     
    The prefix is checked for validity.  If it is a valid ISO 639-1 language code, the lang attribute (lang="ja") is added to the <bdi> tag so that browsers can
    know the language the tag contains.  This may help the browser render the script more correctly.  If the prefix is invalid, the lang attribute
    is not added.  At this time there is no error message for this condition.
     
    Supports |script-title=, |script-chapter=, |script-<periodical>=
     
    ]]
     
    local function format_script_value (script_value, script_param)
    local lang=''; -- initialize to empty string
    local name;
    if script_value:match('^%l%l%l?%s*:') then -- if first 3 or 4 non-space characters are script language prefix
    lang = script_value:match('^(%l%l%l?)%s*:%s*%S.*'); -- get the language prefix or nil if there is no script
    if not utilities.is_set (lang) then
    table.insert( z.message_tail, { utilities.set_message ( 'err_script_parameter', {script_param, 'missing title part'}, true ) } ); -- prefix without 'title'; add error message
    return ''; -- script_value was just the prefix so return empty string
    end
    -- if we get this far we have prefix and script
    name = cfg.lang_code_remap[lang] or mw.language.fetchLanguageName( lang, cfg.this_wiki_code ); -- get language name so that we can use it to categorize
    if utilities.is_set (name) then -- is prefix a proper ISO 639-1 language code?
    script_value = script_value:gsub ('^%l+%s*:%s*', ''); -- strip prefix from script
    -- is prefix one of these language codes?
    if utilities.in_array (lang, cfg.script_lang_codes) then
    utilities.add_prop_cat ('script_with_name', {name, lang})
    else
    table.insert( z.message_tail, { utilities.set_message ( 'err_script_parameter', {script_param, 'unknown language code'}, true ) } ); -- unknown script-language; add error message
    end
    lang = ' lang="' .. lang .. '" '; -- convert prefix into a lang attribute
    else
    table.insert( z.message_tail, { utilities.set_message ( 'err_script_parameter', {script_param, 'invalid language code'}, true ) } ); -- invalid language code; add error message
    lang = ''; -- invalid so set lang to empty string
    end
    else
    table.insert( z.message_tail, { utilities.set_message ( 'err_script_parameter', {script_param, 'missing prefix'}, true ) } ); -- no language code prefix; add error message
    end
    script_value = utilities.substitute (cfg.presentation['bdi'], {lang, script_value}); -- isolate in case script is RTL
     
    return script_value;
    end
    end


    function reducetoinitials(first)
     
        local initials = {}
    --[[--------------------------< S C R I P T _ C O N C A T E N A T E >------------------------------------------
        for word in string.gmatch(first, "%S+") do
     
            table.insert(initials, string.sub(word,1,1)) -- Vancouver format does not include full stops.
    Initially for |title= and |script-title=, this function concatenates those two parameter values after the script value has been
        end
    wrapped in <bdi> tags.
        return table.concat(initials) -- Vancouver format does not include spaces.
    ]]
     
    local function script_concatenate (title, script, script_param)
    if utilities.is_set (script) then
    script = format_script_value (script, script_param); -- <bdi> tags, lang attribute, categorization, etc.; returns empty string on error
    if utilities.is_set (script) then
    title = title .. ' ' .. script; -- concatenate title and script title
    end
    end
    return title;
    end
    end


    function listpeople(control, people)
     
        local sep = control.sep;
    --[[--------------------------< W R A P _ M S G >--------------------------------------------------------------
        if sep:sub(-1,-1) ~= " " then sep = sep .. " " end
     
        local namesep = control.namesep
    Applies additional message text to various parameter values. Supplied string is wrapped using a message_list
        local format = control.format
    configuration taking one argument. Supports lower case text for {{citation}} templates. Additional text taken
        local maximum = control.maximum
    from citation_config.messages - the reason this function is similar to but separate from wrap_style().
        local text = {}
     
        local etal = false;
    ]]
        for i,person in ipairs(people) do
     
            if (person.last ~= nil or person.last ~= "") then
    local function wrap_msg (key, str, lower)
                local mask = person.mask
    if not utilities.is_set ( str ) then
                local one
    return "";
                if ( maximum ~= nil and i == maximum + 1 ) then
    end
                    etal = true;
    if true == lower then
                    break;
    local msg;
                elseif (mask ~= nil) then
    msg = cfg.messages[key]:lower(); -- set the message to lower case before
                    local n = tonumber(mask)
    return utilities.substitute ( msg, str ); -- including template text
                    if (n ~= nil) then
    else
                        one = string.rep("&mdash;",n)
    return utilities.substitute ( cfg.messages[key], str );
                    else
    end
                        one = mask
                    end
                else
                    one = person.last
                    local first = person.first
                    if (first ~= nil) then
                        if ( "vanc" == format ) then first = reducetoinitials(first) end
                        one = one .. namesep .. first
                    end
                    if (person.link ~= nil and person.link ~= "") then one = "[[" .. person.link .. "|" .. one .. "]]" end
                end
                table.insert(text, one)
            end
        end
        local count = #text;
        local result = table.concat(text, sep) -- construct list
        if etal then
            local etal_text = "et al."
            if (sepc == ".") then etal_text = "et al" end
            result = result .. " " .. etal_text;
        end
       
        if ( "scap" == format ) then result= z.mw.text.tag({name="span", contents=result, params={class="smallcaps", style="font-variant:small-caps;"}}) end -- if necessary wrap result in <span> tag to format in Small Caps
        return result, count
    end
    end


    function anchorid(args)
     
        local P1 = args[1] or ""
    --[[----------------< W I K I S O U R C E _ U R L _ M A K E >-------------------
        local P2 = args[2] or ""
     
        local P3 = args[3] or ""
    Makes a Wikisource URL from Wikisource interwiki-link.  Returns the URL and appropriate
        local P4 = args[4] or ""
    label; nil else.
        local P5 = args[5] or ""
     
        return "CITEREF" .. P1 .. P2 .. P3 .. P4 .. P5
    str is the value assigned to |chapter= (or aliases) or |title= or |title-link=
     
    ]]
     
    local function wikisource_url_make (str)
    local wl_type, D, L;
    local ws_url, ws_label;
    local wikisource_prefix = table.concat ({'https://', cfg.this_wiki_code, '.wikisource.org/wiki/'});
     
    wl_type, D, L = utilities.is_wikilink (str); -- wl_type is 0 (not a wikilink), 1 (simple wikilink), 2 (complex wikilink)
     
    if 0 == wl_type then -- not a wikilink; might be from |title-link=
    str = D:match ('^[Ww]ikisource:(.+)') or D:match ('^[Ss]:(.+)'); -- article title from interwiki link with long-form or short-form namespace
    if utilities.is_set (str) then
    ws_url = table.concat ({ -- build a Wikisource URL
    wikisource_prefix, -- prefix
    str, -- article title
    });
    ws_label = str; -- label for the URL
    end
    elseif 1 == wl_type then -- simple wikilink: [[Wikisource:ws article]]
    str = D:match ('^[Ww]ikisource:(.+)') or D:match ('^[Ss]:(.+)'); -- article title from interwiki link with long-form or short-form namespace
    if utilities.is_set (str) then
    ws_url = table.concat ({ -- build a Wikisource URL
    wikisource_prefix, -- prefix
    str, -- article title
    });
    ws_label = str; -- label for the URL
    end
    elseif 2 == wl_type then -- non-so-simple wikilink: [[Wikisource:ws article|displayed text]] ([[L|D]])
    str = L:match ('^[Ww]ikisource:(.+)') or L:match ('^[Ss]:(.+)'); -- article title from interwiki link with long-form or short-form namespace
    if utilities.is_set (str) then
    ws_label = D; -- get ws article name from display portion of interwiki link
    ws_url = table.concat ({ -- build a Wikisource URL
    wikisource_prefix, -- prefix
    str, -- article title without namespace from link portion of wikilink
    });
    end
    end
     
    if ws_url then
    ws_url = mw.uri.encode (ws_url, 'WIKI'); -- make a usable URL
    ws_url = ws_url:gsub ('%%23', '#'); -- undo percent-encoding of fragment marker
    end
     
    return ws_url, ws_label, L or D; -- return proper URL or nil and a label or nil
    end
    end


    function refid(args)
     
        local p = args.p or ""
    --[[----------------< F O R M A T _ P E R I O D I C A L >-----------------------
        local pp = args.pp or ""
     
        local loc = args.loc or ""
    Format the three periodical parameters: |script-<periodical>=, |<periodical>=,
        return anchorid(args) .. p .. pp .. loc   
    and |trans-<periodical>= into a single Periodical meta-parameter.
     
    ]]
     
    local function format_periodical (script_periodical, script_periodical_source, periodical, trans_periodical)
    local periodical_error = '';
     
    if not utilities.is_set (periodical) then
    periodical = ''; -- to be safe for concatenation
    else
    periodical = utilities.wrap_style ('italic-title', periodical); -- style
    end
     
    periodical = script_concatenate (periodical, script_periodical, script_periodical_source); -- <bdi> tags, lang attribute, categorization, etc.; must be done after title is wrapped
     
    if utilities.is_set (trans_periodical) then
    trans_periodical = utilities.wrap_style ('trans-italic-title', trans_periodical);
    if utilities.is_set (periodical) then
    periodical = periodical .. ' ' .. trans_periodical;
    else -- here when trans-periodical without periodical or script-periodical
    periodical = trans_periodical;
    periodical_error = ' ' .. utilities.set_message ('err_trans_missing_title', {'periodical'});
    end
    end
     
    return periodical .. periodical_error;
    end
    end


    function name(args)
     
        local P1 = args[1] or ""
    --[[------------------< F O R M A T _ C H A P T E R _ T I T L E >---------------
        if ( args[5] ~= nil) then
     
            return P1 .. " et al."
    Format the four chapter parameters: |script-chapter=, |chapter=, |trans-chapter=,
        else
    and |chapter-url= into a single chapter meta- parameter (chapter_url_source used
            local P2 = args[2] or ""
    for error messages).
            local P3 = args[3] or ""  
     
            local P4 = args[4] or ""
    ]]
            if ( args[4] ~= nil ) then
     
                P4 = " " .. P4
    local function format_chapter_title (script_chapter, script_chapter_source, chapter, chapter_source, trans_chapter, trans_chapter_source, chapter_url, chapter_url_source, no_quotes, access)
                P3 = ", & " .. P3
    local chapter_error = '';
                P2 = ", " .. P2
     
            elseif ( args[3] ~= nil ) then
    local ws_url, ws_label, L = wikisource_url_make (chapter); -- make a wikisource URL and label from a wikisource interwiki link
                P3 = " " .. P3
    if ws_url then
                P2 = " & " .. P2
    ws_label = ws_label:gsub ('_', ' '); -- replace underscore separators with space characters
            elseif ( args[2] ~= nil ) then
    chapter = ws_label;
                P2 = " " .. P2           
    end
            end
     
            return P1 .. P2 .. P3 .. P4
    if not utilities.is_set (chapter) then
        end  
    chapter = ''; -- to be safe for concatenation
    else
    if false == no_quotes then
    chapter = kern_quotes (chapter); -- if necessary, separate chapter title's leading and trailing quote marks from module provided quote marks
    chapter = utilities.wrap_style ('quoted-title', chapter);
    end
    end
     
    chapter = script_concatenate (chapter, script_chapter, script_chapter_source); -- <bdi> tags, lang attribute, categorization, etc.; must be done after title is wrapped
     
    if utilities.is_set (chapter_url) then
    chapter = external_link (chapter_url, chapter, chapter_url_source, access); -- adds bare_url_missing_title error if appropriate
    elseif ws_url then
    chapter = external_link (ws_url, chapter .. '&nbsp;', 'ws link in chapter'); -- adds bare_url_missing_title error if appropriate; space char to move icon away from chap text; TODO: better way to do this?
    chapter = utilities.substitute (cfg.presentation['interwiki-icon'], {cfg.presentation['class-wikisource'], L, chapter});
    end
     
    if utilities.is_set (trans_chapter) then
    trans_chapter = utilities.wrap_style ('trans-quoted-title', trans_chapter);
    if utilities.is_set (chapter) then
    chapter = chapter .. ' ' .. trans_chapter;
    else -- here when trans_chapter without chapter or script-chapter
    chapter = trans_chapter;
    chapter_source = trans_chapter_source:match ('trans%-?(.+)'); -- when no chapter, get matching name from trans-<param>
    chapter_error = ' ' .. utilities.set_message ('err_trans_missing_title', {chapter_source});
    end
    end
     
    return chapter .. chapter_error;
    end
     
     
    --[[----------------< H A S _ I N V I S I B L E _ C H A R S >-------------------
     
    This function searches a parameter's value for non-printable or invisible characters.
    The search stops at the first match.
     
    This function will detect the visible replacement character when it is part of the Wikisource.
     
    Detects but ignores nowiki and math stripmarkers.  Also detects other named stripmarkers
    (gallery, math, pre, ref) and identifies them with a slightly different error message.
    See also coins_cleanup().
     
    Output of this function is an error message that identifies the character or the
    Unicode group, or the stripmarker that was detected along with its position (or,
    for multi-byte characters, the position of its first byte) in the parameter value.
     
    ]]
     
    local function has_invisible_chars (param, v)
    local position = ''; -- position of invisible char or starting position of stripmarker
    local capture; -- used by stripmarker detection to hold name of the stripmarker
    local stripmarker; -- boolean set true when a stripmarker is found
     
    capture = string.match (v, '[%w%p ]*'); -- test for values that are simple ASCII text and bypass other tests if true
    if capture == v then -- if same there are no Unicode characters
    return;
    end
     
    for _, invisible_char in ipairs (cfg.invisible_chars) do
    local char_name = invisible_char[1]; -- the character or group name
    local pattern = invisible_char[2]; -- the pattern used to find it
    position, _, capture = mw.ustring.find (v, pattern); -- see if the parameter value contains characters that match the pattern
    if position and (cfg.invisible_defs.zwj == capture) then -- if we found a zero-width joiner character
    if mw.ustring.find (v, cfg.indic_script) then -- it's ok if one of the Indic scripts
    position = nil; -- unset position
    elseif cfg.emoji[mw.ustring.codepoint (v, position+1)] then -- is zwj followed by a character listed in emoji{}?
    position = nil; -- unset position
    end
    end
    if position then
    if 'nowiki' == capture or 'math' == capture or -- nowiki and math stripmarkers (not an error condition)
    ('templatestyles' == capture and utilities.in_array (param, {'id', 'quote'})) then -- templatestyles stripmarker allowed in these parameters
    stripmarker = true; -- set a flag
    elseif true == stripmarker and cfg.invisible_defs.del == capture then -- because stripmakers begin and end with the delete char, assume that we've found one end of a stripmarker
    position = nil; -- unset
    else
    local err_msg;
    if capture and not (cfg.invisible_defs.del == capture or cfg.invisible_defs.zwj == capture) then
    err_msg = capture .. ' ' .. char_name;
    else
    err_msg = char_name .. ' ' .. 'character';
    end
     
    table.insert (z.message_tail, {utilities.set_message ('err_invisible_char', {err_msg, utilities.wrap_style ('parameter', param), position}, true)}); -- add error message
    return; -- and done with this parameter
    end
    end
    end
    end
     
     
    --[[-------------------< A R G U M E N T _ W R A P P E R >----------------------
     
    Argument wrapper.  This function provides support for argument mapping defined
    in the configuration file so that multiple names can be transparently aliased to
    single internal variable.
     
    ]]
     
    local function argument_wrapper ( args )
    local origin = {};
    return setmetatable({
    ORIGIN = function ( self, k )
    local dummy = self[k]; -- force the variable to be loaded.
    return origin[k];
    end
    },
    {
    __index = function ( tbl, k )
    if origin[k] ~= nil then
    return nil;
    end
    local args, list, v = args, cfg.aliases[k];
    if type( list ) == 'table' then
    v, origin[k] = utilities.select_one ( args, list, 'err_redundant_parameters' );
    if origin[k] == nil then
    origin[k] = ''; -- Empty string, not nil
    end
    elseif list ~= nil then
    v, origin[k] = args[list], list;
    else
    -- maybe let through instead of raising an error?
    -- v, origin[k] = args[k], k;
    error( cfg.messages['unknown_argument_map'] .. ': ' .. k);
    end
    -- Empty strings, not nil;
    if v == nil then
    v = '';
    origin[k] = '';
    end
    tbl = rawset( tbl, k, v );
    return v;
    end,
    });
    end
     
     
    --[[--------------------------< N O W R A P _ D A T E >-------------------------
     
    When date is YYYY-MM-DD format wrap in nowrap span: <span ...>YYYY-MM-DD</span>.
    When date is DD MMMM YYYY or is MMMM DD, YYYY then wrap in nowrap span:
    <span ...>DD MMMM</span> YYYY or <span ...>MMMM DD,</span> YYYY
     
    DOES NOT yet support MMMM YYYY or any of the date ranges.
     
    ]]
     
    local function nowrap_date (date)
    local cap = '';
    local cap2 = '';
     
    if date:match("^%d%d%d%d%-%d%d%-%d%d$") then
    date = utilities.substitute (cfg.presentation['nowrap1'], date);
    elseif date:match("^%a+%s*%d%d?,%s+%d%d%d%d$") or date:match ("^%d%d?%s*%a+%s+%d%d%d%d$") then
    cap, cap2 = string.match (date, "^(.*)%s+(%d%d%d%d)$");
    date = utilities.substitute (cfg.presentation['nowrap2'], {cap, cap2});
    end
    return date;
    end
     
     
    --[[--------------------------< S E T _ T I T L E T Y P E >---------------------
     
    This function sets default title types (equivalent to the citation including
    |type=<default value>) for those templates that have defaults. Also handles the
    special case where it is desirable to omit the title type from the rendered citation
    (|type=none).
     
    ]]
     
    local function set_titletype (cite_class, title_type)
    if utilities.is_set (title_type) then
    if 'none' == cfg.keywords_xlate[title_type] then
    title_type = ''; -- if |type=none then type parameter not displayed
    end
    return title_type; -- if |type= has been set to any other value use that value
    end
     
    return cfg.title_types [cite_class] or ''; -- set template's default title type; else empty string for concatenation
    end
     
     
    --[[--------------------------< H Y P H E N _ T O _ D A S H >--------------------------------------------------
     
    Converts a hyphen to a dash under certain conditions.  The hyphen must separate
    like items; unlike items are returned unmodified.  These forms are modified:
    letter - letter (A - B)
    digit - digit (4-5)
    digit separator digit - digit separator digit (4.1-4.5 or 4-1-4-5)
    letterdigit - letterdigit (A1-A5) (an optional separator between letter and
    digit is supported – a.1-a.5 or a-1-a-5)
    digitletter - digitletter (5a - 5d) (an optional separator between letter and
    digit is supported – 5.a-5.d or 5-a-5-d)
     
    any other forms are returned unmodified.
     
    str may be a comma- or semicolon-separated list
     
    ]]
     
    local function hyphen_to_dash( str )
    if not utilities.is_set (str) then
    return str;
    end
     
    local accept; -- Boolean
     
    str = str:gsub ('&[nm]dash;', {['&ndash;'] = '–', ['&mdash;'] = '—'}); -- replace &mdash; and &ndash; entities with their characters; semicolon mucks up the text.split
    str = str:gsub ('&#45;', '-'); -- replace HTML numeric entity with hyphen character
     
    str = str:gsub ('&nbsp;', ' '); -- replace &nbsp; entity with generic keyboard space character
    local out = {};
    local list = mw.text.split (str, '%s*[,;]%s*'); -- split str at comma or semicolon separators if there are any
     
    for _, item in ipairs (list) do -- for each item in the list
    item, accept = utilities.has_accept_as_written (item); -- remove accept-this-as-written markup when it wraps all of item
    if not accept and mw.ustring.match (item, '^%w*[%.%-]?%w+%s*[%-–—]%s*%w*[%.%-]?%w+$') then -- if a hyphenated range or has endash or emdash separators
    if item:match ('^%a+[%.%-]?%d+%s*%-%s*%a+[%.%-]?%d+$') or -- letterdigit hyphen letterdigit (optional separator between letter and digit)
    item:match ('^%d+[%.%-]?%a+%s*%-%s*%d+[%.%-]?%a+$') or -- digitletter hyphen digitletter (optional separator between digit and letter)
    item:match ('^%d+[%.%-]%d+%s*%-%s*%d+[%.%-]%d+$') or -- digit separator digit hyphen digit separator digit
    item:match ('^%d+%s*%-%s*%d+$') or -- digit hyphen digit
    item:match ('^%a+%s*%-%s*%a+$') then -- letter hyphen letter
    item = item:gsub ('(%w*[%.%-]?%w+)%s*%-%s*(%w*[%.%-]?%w+)', '%1–%2'); -- replace hyphen, remove extraneous space characters
    else
    item = mw.ustring.gsub (item, '%s*[–—]%s*', '–'); -- for endash or emdash separated ranges, replace em with en, remove extraneous whitespace
    end
    end
    table.insert (out, item); -- add the (possibly modified) item to the output table
    end
     
    local temp_str = ''; -- concatenate the output table into a comma separated string
    temp_str, accept = utilities.has_accept_as_written (table.concat (out, ', ')); -- remove accept-this-as-written markup when it wraps all of concatenated out
    if accept then
    temp_str = utilities.has_accept_as_written (str); -- when global markup removed, return original str; do it this way to suppress boolean second return value
    return temp_str;
    else
    return temp_str; -- else, return assembled temp_str
    end
    end
     
     
    --[[--------------------------< S A F E _ J O I N >-----------------------------
     
    Joins a sequence of strings together while checking for duplicate separation characters.
     
    ]]
     
    local function safe_join( tbl, duplicate_char )
    local f = {}; -- create a function table appropriate to type of 'duplicate character'
    if 1 == #duplicate_char then -- for single byte ASCII characters use the string library functions
    f.gsub = string.gsub
    f.match = string.match
    f.sub = string.sub
    else -- for multi-byte characters use the ustring library functions
    f.gsub = mw.ustring.gsub
    f.match = mw.ustring.match
    f.sub = mw.ustring.sub
    end
     
    local str = ''; -- the output string
    local comp = ''; -- what does 'comp' mean?
    local end_chr = '';
    local trim;
    for _, value in ipairs( tbl ) do
    if value == nil then value = ''; end
    if str == '' then -- if output string is empty
    str = value; -- assign value to it (first time through the loop)
    elseif value ~= '' then
    if value:sub(1, 1) == '<' then -- special case of values enclosed in spans and other markup.
    comp = value:gsub( "%b<>", "" ); -- remove HTML markup (<span>string</span> -> string)
    else
    comp = value;
    end
    -- typically duplicate_char is sepc
    if f.sub(comp, 1, 1) == duplicate_char then -- is first character same as duplicate_char? why test first character?
    --  Because individual string segments often (always?) begin with terminal punct for the
    --  preceding segment: 'First element' .. 'sepc next element' .. etc.?
    trim = false;
    end_chr = f.sub(str, -1, -1); -- get the last character of the output string
    -- str = str .. "<HERE(enchr=" .. end_chr .. ")" -- debug stuff?
    if end_chr == duplicate_char then -- if same as separator
    str = f.sub(str, 1, -2); -- remove it
    elseif end_chr == "'" then -- if it might be wiki-markup
    if f.sub(str, -3, -1) == duplicate_char .. "''" then -- if last three chars of str are sepc''
    str = f.sub(str, 1, -4) .. "''"; -- remove them and add back ''
    elseif  f.sub(str, -5, -1) == duplicate_char .. "]]''" then -- if last five chars of str are sepc]]''
    trim = true; -- why? why do this and next differently from previous?
    elseif f.sub(str, -4, -1) == duplicate_char .. "]''" then -- if last four chars of str are sepc]''
    trim = true; -- same question
    end
    elseif end_chr == "]" then -- if it might be wiki-markup
    if f.sub(str, -3, -1) == duplicate_char .. "]]" then -- if last three chars of str are sepc]] wikilink
    trim = true;
    elseif f.sub(str, -3, -1) == duplicate_char .. '"]' then -- if last three chars of str are sepc"] quoted external link
    trim = true;
    elseif  f.sub(str, -2, -1) == duplicate_char .. "]" then -- if last two chars of str are sepc] external link
    trim = true;
    elseif f.sub(str, -4, -1) == duplicate_char .. "'']" then -- normal case when |url=something & |title=Title.
    trim = true;
    end
    elseif end_chr == " " then -- if last char of output string is a space
    if f.sub(str, -2, -1) == duplicate_char .. " " then -- if last two chars of str are <sepc><space>
    str = f.sub(str, 1, -3); -- remove them both
    end
    end
     
    if trim then
    if value ~= comp then -- value does not equal comp when value contains HTML markup
    local dup2 = duplicate_char;
    if f.match(dup2, "%A" ) then dup2 = "%" .. dup2; end -- if duplicate_char not a letter then escape it
    value = f.gsub(value, "(%b<>)" .. dup2, "%1", 1 ) -- remove duplicate_char if it follows HTML markup
    else
    value = f.sub(value, 2, -1 ); -- remove duplicate_char when it is first character
    end
    end
    end
    str = str .. value; -- add it to the output string
    end
    end
    return str;
    end
     
     
    --[[--------------------------< I S _ S U F F I X >-----------------------------
     
    returns true is suffix is properly formed Jr, Sr, or ordinal in the range 1–9.
    Puncutation not allowed.
     
    ]]
     
    local function is_suffix (suffix)
    if utilities.in_array (suffix, {'Jr', 'Sr', 'Jnr', 'Snr', '1st', '2nd', '3rd'}) or suffix:match ('^%dth$') then
    return true;
    end
    return false;
    end
     
     
    --[[--------------------< I S _ G O O D _ V A N C _ N A M E >-------------------
     
    For Vancouver style, author/editor names are supposed to be rendered in Latin
    (read ASCII) characters.  When a name uses characters that contain diacritical
    marks, those characters are to be converted to the corresponding Latin
    character. When a name is written using a non-Latin alphabet or logogram, that
    name is to be transliterated into Latin characters. The module doesn't do this
    so editors may/must.
     
    This test allows |first= and |last= names to contain any of the letters defined
    in the four Unicode Latin character sets
    [http://www.unicode.org/charts/PDF/U0000.pdf C0 Controls and Basic Latin] 0041–005A, 0061–007A
    [http://www.unicode.org/charts/PDF/U0080.pdf C1 Controls and Latin-1 Supplement] 00C0–00D6, 00D8–00F6, 00F8–00FF
    [http://www.unicode.org/charts/PDF/U0100.pdf Latin Extended-A] 0100–017F
    [http://www.unicode.org/charts/PDF/U0180.pdf Latin Extended-B] 0180–01BF, 01C4–024F
     
    |lastn= also allowed to contain hyphens, spaces, and apostrophes.
    (http://www.ncbi.nlm.nih.gov/books/NBK7271/box/A35029/)
    |firstn= also allowed to contain hyphens, spaces, apostrophes, and periods
     
    This original test:
    if nil == mw.ustring.find (last, "^[A-Za-zÀ-ÖØ-öø-ƿDŽ-ɏ%-%s%']*$")
    or nil == mw.ustring.find (first, "^[A-Za-zÀ-ÖØ-öø-ƿDŽ-ɏ%-%s%'%.]+[2-6%a]*$") then
    was written outside of the code editor and pasted here because the code editor
    gets confused between character insertion point and cursor position. The test has
    been rewritten to use decimal character escape sequence for the individual bytes
    of the Unicode characters so that it is not necessary to use an external editor
    to maintain this code.
     
    \195\128-\195\150 – À-Ö (U+00C0–U+00D6 – C0 controls)
    \195\152-\195\182 – Ø-ö (U+00D8-U+00F6 – C0 controls)
    \195\184-\198\191 – ø-ƿ (U+00F8-U+01BF – C0 controls, Latin extended A & B)
    \199\132-\201\143 – DŽ-ɏ (U+01C4-U+024F – Latin extended B)
     
    ]]
     
    local function is_good_vanc_name (last, first, suffix, position)
    if not suffix then
    if first:find ('[,%s]') then -- when there is a space or comma, might be first name/initials + generational suffix
    first = first:match ('(.-)[,%s]+'); -- get name/initials
    suffix = first:match ('[,%s]+(.+)$'); -- get generational suffix
    end
    end
    if utilities.is_set (suffix) then
    if not is_suffix (suffix) then
    add_vanc_error (cfg.err_msg_supl.suffix, position);
    return false; -- not a name with an appropriate suffix
    end
    end
    if nil == mw.ustring.find (last, "^[A-Za-z\195\128-\195\150\195\152-\195\182\195\184-\198\191\199\132-\201\143%-%s%']*$") or
    nil == mw.ustring.find (first, "^[A-Za-z\195\128-\195\150\195\152-\195\182\195\184-\198\191\199\132-\201\143%-%s%'%.]*$") then
    add_vanc_error (cfg.err_msg_supl['non-Latin char'], position);
    return false; -- not a string of Latin characters; Vancouver requires Romanization
    end;
    return true;
    end
     
     
    --[[--------------------------< R E D U C E _ T O _ I N I T I A L S >------------------------------------------
     
    Attempts to convert names to initials in support of |name-list-style=vanc. 
     
    Names in |firstn= may be separated by spaces or hyphens, or for initials, a period.
    See http://www.ncbi.nlm.nih.gov/books/NBK7271/box/A35062/.
     
    Vancouver style requires family rank designations (Jr, II, III, etc.) to be rendered
    as Jr, 2nd, 3rd, etc.  See http://www.ncbi.nlm.nih.gov/books/NBK7271/box/A35085/.
    This code only accepts and understands generational suffix in the Vancouver format
    because Roman numerals look like, and can be mistaken for, initials.
     
    This function uses ustring functions because firstname initials may be any of the
    Unicode Latin characters accepted by is_good_vanc_name ().
     
    ]]
     
    local function reduce_to_initials(first, position)
    local name, suffix = mw.ustring.match(first, "^(%u+) ([%dJS][%drndth]+)$");
     
    if not name then -- if not initials and a suffix
    name = mw.ustring.match(first, "^(%u+)$"); -- is it just initials?
    end
     
    if name then -- if first is initials with or without suffix
    if 3 > mw.ustring.len (name) then -- if one or two initials
    if suffix then -- if there is a suffix
    if is_suffix (suffix) then -- is it legitimate?
    return first; -- one or two initials and a valid suffix so nothing to do
    else
    add_vanc_error (cfg.err_msg_supl.suffix, position); -- one or two initials with invalid suffix so error message
    return first; -- and return first unmolested
    end
    else
    return first; -- one or two initials without suffix; nothing to do
    end
    end
    end -- if here then name has 3 or more uppercase letters so treat them as a word
     
    local initials, names = {}, {}; -- tables to hold name parts and initials
    local i = 1; -- counter for number of initials
     
    names = mw.text.split (first, '[%s,]+'); -- split into a table of names and possible suffix
     
    while names[i] do -- loop through the table
    if 1 < i and names[i]:match ('[%dJS][%drndth]+%.?$') then -- if not the first name, and looks like a suffix (may have trailing dot)
    names[i] = names[i]:gsub ('%.', ''); -- remove terminal dot if present
    if is_suffix (names[i]) then -- if a legitimate suffix
    table.insert (initials, ' ' .. names[i]); -- add a separator space, insert at end of initials table
    break; -- and done because suffix must fall at the end of a name
    end -- no error message if not a suffix; possibly because of Romanization
    end
    if 3 > i then
    table.insert (initials, mw.ustring.sub(names[i], 1, 1)); -- insert the initial at end of initials table
    end
    i = i + 1; -- bump the counter
    end
    return table.concat(initials) -- Vancouver format does not include spaces.
    end
     
     
    --[[--------------------------< L I S T _ P E O P L E >--------------------------
     
    Formats a list of people (authors, contributors, editors, interviewers, translators)
     
    names in the list will be linked when
    |<name>-link= has a value
    |<name>-mask- does NOT have a value; masked names are presumed to have been
    rendered previously so should have been linked there
     
    when |<name>-mask=0, the associated name is not rendered
     
    ]]
     
    local function list_people (control, people, etal)
    local sep;
    local namesep;
    local format = control.format;
    local maximum = control.maximum;
    local name_list = {};
     
    if 'vanc' == format then -- Vancouver-like name styling?
    sep = cfg.presentation['sep_nl_vanc']; -- name-list separator between names is a comma
    namesep = cfg.presentation['sep_name_vanc']; -- last/first separator is a space
    else
    sep = cfg.presentation['sep_nl']; -- name-list separator between names is a semicolon
    namesep = cfg.presentation['sep_name']; -- last/first separator is <comma><space>
    end
    if sep:sub (-1, -1) ~= " " then sep = sep .. " " end
    if utilities.is_set (maximum) and maximum < 1 then return "", 0; end -- returned 0 is for EditorCount; not used for other names
    for i, person in ipairs (people) do
    if utilities.is_set (person.last) then
    local mask = person.mask;
    local one;
    local sep_one = sep;
     
    if utilities.is_set (maximum) and i > maximum then
    etal = true;
    break;
    end
    if mask then
    local n = tonumber (mask); -- convert to a number if it can be converted; nil else
    if n then
    one = 0 ~= n and string.rep("&mdash;", n) or nil; -- make a string of (n > 0) mdashes, nil else, to replace name
    person.link = nil; -- don't create link to name if name is replaces with mdash string or has been set nil
    else
    one = mask; -- replace name with mask text (must include name-list separator)
    sep_one = " "; -- modify name-list separator
    end
    else
    one = person.last; -- get surname
    local first = person.first -- get given name
    if utilities.is_set (first) then
    if ("vanc" == format) then -- if Vancouver format
    one = one:gsub ('%.', ''); -- remove periods from surnames (http://www.ncbi.nlm.nih.gov/books/NBK7271/box/A35029/)
    if not person.corporate and is_good_vanc_name (one, first, nil, i) then -- and name is all Latin characters; corporate authors not tested
    first = reduce_to_initials (first, i); -- attempt to convert first name(s) to initials
    end
    end
    one = one .. namesep .. first;
    end
    end
    if utilities.is_set (person.link) then
    one = utilities.make_wikilink (person.link, one); -- link author/editor
    end
    if one then -- if <one> has a value (name, mdash replacement, or mask text replacement)
    table.insert (name_list, one); -- add it to the list of names
    table.insert (name_list, sep_one); -- add the proper name-list separator
    end
    end
    end
     
    local count = #name_list / 2; -- (number of names + number of separators) divided by 2
    if 0 < count then
    if 1 < count and not etal then
    if 'amp' == format then
    name_list[#name_list-2] = " & "; -- replace last separator with ampersand text
    elseif 'and' == format then
    if 2 == count then
    name_list[#name_list-2] = cfg.presentation.sep_nl_and; -- replace last separator with 'and' text
    else
    name_list[#name_list-2] = cfg.presentation.sep_nl_end; -- replace last separator with '(sep) and' text
    end
    end
    end
    name_list[#name_list] = nil; -- erase the last separator
    end
     
    local result = table.concat (name_list); -- construct list
    if etal and utilities.is_set (result) then -- etal may be set by |display-authors=etal but we might not have a last-first list
    result = result .. sep .. ' ' .. cfg.messages['et al']; -- we've got a last-first list and etal so add et al.
    end
    return result, count; -- return name-list string and count of number of names (count used for editor names only)
    end
     
    --[[--------------------< M A K E _ C I T E R E F _ I D >-----------------------
     
    Generates a CITEREF anchor ID if we have at least one name or a date.  Otherwise
    returns an empty string.
     
    namelist is one of the contributor-, author-, or editor-name lists chosen in that
    order.  year is Year or anchor_year.
     
    ]]
     
    local function make_citeref_id (namelist, year)
    local names={}; -- a table for the one to four names and year
    for i,v in ipairs (namelist) do -- loop through the list and take up to the first four last names
    names[i] = v.last
    if i == 4 then break end -- if four then done
    end
    table.insert (names, year); -- add the year at the end
    local id = table.concat(names); -- concatenate names and year for CITEREF id
    if utilities.is_set (id) then -- if concatenation is not an empty string
    return "CITEREF" .. id; -- add the CITEREF portion
    else
    return ''; -- return an empty string; no reason to include CITEREF id in this citation
    end
    end
     
     
    --[[---------------------< N A M E _ H A S _ E T A L >--------------------------
     
    Evaluates the content of name parameters (author, editor, etc.) for variations on
    the theme of et al.  If found, the et al. is removed, a flag is set to true and
    the function returns the modified name and the flag.
     
    This function never sets the flag to false but returns its previous state because
    it may have been set by previous passes through this function or by the associated
    |display-<names>=etal parameter
     
    ]]
     
    local function name_has_etal (name, etal, nocat, param)
     
    if utilities.is_set (name) then -- name can be nil in which case just return
    local patterns = cfg.et_al_patterns; -- get patterns from configuration
    for _, pattern in ipairs (patterns) do -- loop through all of the patterns
    if name:match (pattern) then -- if this 'et al' pattern is found in name
    name = name:gsub (pattern, ''); -- remove the offending text
    etal = true; -- set flag (may have been set previously here or by |display-<names>=etal)
    if not nocat then -- no categorization for |vauthors=
    table.insert( z.message_tail, {utilities.set_message ('err_etal', {param})}); -- and set an error if not added
    end
    end
    end
    end
     
    return name, etal;
    end
     
     
    --[[---------------------< N A M E _ I S _ N U M E R I C >----------------------
     
    Add maint cat when name parameter value does not contain letters.  Does not catch
    mixed alphanumeric names so |last=A. Green (1922-1987) does not get caught in the
    current version of this test but |first=(1888) is caught.
     
    returns nothing
     
    ]]
     
    local function name_is_numeric (name, list_name)
    if utilities.is_set (name) then
    if mw.ustring.match (name, '^[%A]+$') then -- when name does not contain any letters
    utilities.set_message ('maint_numeric_names', cfg.special_case_translation [list_name]); -- add a maint cat for this template
    end
    end
    end
     
     
    --[[-------------------< N A M E _ H A S _ E D _ M A R K U P >------------------
     
    Evaluates the content of author and editor parameters for extraneous editor annotations:
    ed, ed., eds, (Ed.), etc. These annotations do not belong in author parameters and
    are redundant in editor parameters.  If found, the function adds the editor markup
    maintenance category.
     
    returns nothing
     
    ]]
     
    local function name_has_ed_markup (name, list_name)
    local patterns = cfg.editor_markup_patterns; -- get patterns from configuration
     
    if utilities.is_set (name) then
    for _, pattern in ipairs (patterns) do -- spin through patterns table and
    if name:match (pattern) then
    utilities.set_message ('maint_extra_text_names', cfg.special_case_translation [list_name]); -- add a maint cat for this template
    break;
    end
    end
    end
    end
     
     
    --[[-----------------< N A M E _ H A S _ M U L T _ N A M E S >------------------
     
    Evaluates the content of last/surname (authors etc.) parameters for multiple names.
    Multiple names are indicated if there is more than one comma or any "unescaped"
    semicolons. Escaped semicolons are ones used as part of selected HTML entities.
    If the condition is met, the function adds the multiple name maintenance category.
     
    returns nothing
     
    ]]
     
    local function name_has_mult_names (name, list_name)
    local _, commas, semicolons, nbsps;
    if utilities.is_set (name) then
    _, commas = name:gsub (',', ''); -- count the number of commas
    _, semicolons = name:gsub (';', ''); -- count the number of semicolons
    -- nbsps probably should be its own separate count rather than merged in
    -- some way with semicolons because Lua patterns do not support the
    -- grouping operator that regex does, which means there is no way to add
    -- more entities to escape except by adding more counts with the new
    -- entities
    _, nbsps = name:gsub ('&nbsp;',''); -- count nbsps
    -- There is exactly 1 semicolon per &nbsp; entity, so subtract nbsps
    -- from semicolons to 'escape' them. If additional entities are added,
    -- they also can be subtracted.
    if 1 < commas or 0 < (semicolons - nbsps) then
    utilities.set_message ('maint_mult_names', cfg.special_case_translation [list_name]); -- add a maint message
    end
    end
    end
     
     
    --[[------------------------< N A M E _ C H E C K S >---------------------------
     
    This function calls various name checking functions used to validate the content
    of the various name-holding parameters.
     
    ]]
     
    local function name_checks (last, first, list_name)
    local accept_name;
     
    if utilities.is_set (last) then
    last, accept_name = utilities.has_accept_as_written (last); -- remove accept-this-as-written markup when it wraps all of <last>
    if not accept_name then -- <last> not wrapped in accept-as-written markup
    name_has_mult_names (last, list_name); -- check for multiple names in the parameter (last only)
    name_has_ed_markup (last, list_name); -- check for extraneous 'editor' annotation
    name_is_numeric (last, list_name); -- check for names that are composed of digits and punctuation
    end
    end
     
    if utilities.is_set (first) then
    first, accept_name = utilities.has_accept_as_written (first); -- remove accept-this-as-written markup when it wraps all of <first>
     
    if not accept_name then -- <first> not wrapped in accept-as-written markup
    name_has_ed_markup (first, list_name); -- check for extraneous 'editor' annotation
    name_is_numeric (first, list_name); -- check for names that are composed of digits and punctuation
    end
    end
     
    return last, first; -- done
    end
     
     
    --[[----------------------< E X T R A C T _ N A M E S >-------------------------
    Gets name list from the input arguments
     
    Searches through args in sequential order to find |lastn= and |firstn= parameters
    (or their aliases), and their matching link and mask parameters. Stops searching
    when both |lastn= and |firstn= are not found in args after two sequential attempts:
    found |last1=, |last2=, and |last3= but doesn't find |last4= and |last5= then the
    search is done.
     
    This function emits an error message when there is a |firstn= without a matching
    |lastn=.  When there are 'holes' in the list of last names, |last1= and |last3=
    are present but |last2= is missing, an error message is emitted. |lastn= is not
    required to have a matching |firstn=.
     
    When an author or editor parameter contains some form of 'et al.', the 'et al.'
    is stripped from the parameter and a flag (etal) returned that will cause list_people()
    to add the static 'et al.' text from Module:Citation/CS1/Configuration.  This keeps
    'et al.' out of the template's metadata.  When this occurs, an error is emitted.
     
    ]]
     
    local function extract_names(args, list_name)
    local names = {}; -- table of names
    local last; -- individual name components
    local first;
    local link;
    local mask;
    local i = 1; -- loop counter/indexer
    local n = 1; -- output table indexer
    local count = 0; -- used to count the number of times we haven't found a |last= (or alias for authors, |editor-last or alias for editors)
    local etal = false; -- return value set to true when we find some form of et al. in an author parameter
     
    local last_alias, first_alias, link_alias; -- selected parameter aliases used in error messaging
    while true do
    last, last_alias = utilities.select_one ( args, cfg.aliases[list_name .. '-Last'], 'err_redundant_parameters', i ); -- search through args for name components beginning at 1
    first, first_alias = utilities.select_one ( args, cfg.aliases[list_name .. '-First'], 'err_redundant_parameters', i );
    link, link_alias = utilities.select_one ( args, cfg.aliases[list_name .. '-Link'], 'err_redundant_parameters', i );
    mask = utilities.select_one ( args, cfg.aliases[list_name .. '-Mask'], 'err_redundant_parameters', i );
     
    last, etal = name_has_etal (last, etal, false, last_alias); -- find and remove variations on et al.
    first, etal = name_has_etal (first, etal, false, first_alias); -- find and remove variations on et al.
    last, first = name_checks (last, first, list_name); -- multiple names, extraneous annotation, etc. checks
    if first and not last then -- if there is a firstn without a matching lastn
    local alias = first_alias:find ('given', 1, true) and 'given' or 'first'; -- get first or given form of the alias
    table.insert (z.message_tail, { utilities.set_message ( 'err_first_missing_last', {
    first_alias, -- param name of alias missing its mate
    first_alias:gsub (alias, {['first'] = 'last', ['given'] = 'surname'}), -- make param name appropriate to the alias form
    }, true ) } ); -- add this error message
    elseif not first and not last then -- if both firstn and lastn aren't found, are we done?
    count = count + 1; -- number of times we haven't found last and first
    if 2 <= count then -- two missing names and we give up
    break; -- normal exit or there is a two-name hole in the list; can't tell which
    end
    else -- we have last with or without a first
    local result;
    link = link_title_ok (link, link_alias, last, last_alias); -- check for improper wiki-markup
    if first then
    link = link_title_ok (link, link_alias, first, first_alias); -- check for improper wiki-markup
    end
     
    names[n] = {last = last, first = first, link = link, mask = mask, corporate = false}; -- add this name to our names list (corporate for |vauthors= only)
    n = n + 1; -- point to next location in the names table
    if 1 == count then -- if the previous name was missing
    table.insert( z.message_tail, { utilities.set_message ( 'err_missing_name', {list_name:match ("(%w+)List"):lower(), i - 1}, true ) } ); -- add this error message
    end
    count = 0; -- reset the counter, we're looking for two consecutive missing names
    end
    i = i + 1; -- point to next args location
    end
    return names, etal; -- all done, return our list of names and the etal flag
    end
     
     
    --[[---------------------< G E T _ I S O 6 3 9 _ C O D E >----------------------
     
    Validates language names provided in |language= parameter if not an ISO639-1 or 639-2 code.
     
    Returns the language name and associated two- or three-character code.  Because
    case of the source may be incorrect or different from the case that WikiMedia uses,
    the name comparisons are done in lower case and when a match is found, the Wikimedia
    version (assumed to be correct) is returned along with the code.  When there is no
    match, we return the original language name string.
     
    mw.language.fetchLanguageNames(<local wiki language>, 'all') returns a list of
    languages that in some cases may include extensions. For example, code 'cbk-zam'
    and its associated name 'Chavacano de Zamboanga' (MediaWiki does not support
    code 'cbk' or name 'Chavacano'.  Most (all?) of these languages are not used a
    'language' codes per se, rather they are used as sub-domain names: cbk-zam.wikipedia.org.
    A list of language names and codes supported by fetchLanguageNames() can be found
    at Template:Citation Style documentation/language/doc
     
    Names that are included in the list will be found if that name is provided in the
    |language= parameter. For example, if |language=Chavacano de Zamboanga, that name
    will be found with the associated code 'cbk-zam'. When names are found and the
    associated code is not two or three characters, this function returns only the
    WikiMedia language name.
     
    Some language names have multiple entries under different codes:
    Aromanian has code rup and code roa-rup
    When this occurs, this function returns the language name and the 2- or 3-character code
     
    Adapted from code taken from Module:Check ISO 639-1.
     
    ]]
     
    local function get_iso639_code (lang, this_wiki_code)
    if cfg.lang_name_remap[lang:lower()] then -- if there is a remapped name (because MediaWiki uses something that we don't think is correct)
    return cfg.lang_name_remap[lang:lower()][1], cfg.lang_name_remap[lang:lower()][2]; -- for this language 'name', return a possibly new name and appropriate code
    end
     
    local ietf_code; -- because some languages have both IETF-like codes and ISO 639-like codes
    local ietf_name;
    local langlc = mw.ustring.lower (lang); -- lower-case version for comparisons
     
    for code, name in pairs (cfg.languages) do -- scan the list to see if we can find our language
    if langlc == mw.ustring.lower (name) then
    if 2 == #code or 3 == #code then -- two- or three-character codes only; IETF extensions not supported
    return name, code; -- so return the name and the code
    end
    ietf_code = code; -- remember that we found an IETF-like code and save its name
    ietf_name = name; -- but keep looking for a 2- or 3-char code
    end
    end
    -- didn't find name with 2- or 3-char code; if IETF-like code found return
    return ietf_code and ietf_name or lang; -- associated name; return original language text else
    end
    end


    function crossref(frame, args)
     
        local config = frame.args -- the arguments passed BY the template, in the wikitext of the template itself
    --[[-------------------< L A N G U A G E _ P A R A M E T E R >------------------
        local LB = config.BracketLeft or ""
     
        local RB = config.BracketRight or ""
    Gets language name from a provided two- or three-character ISO 639 code.  If a code
        local anchor = args.ref or args.Ref or anchorid(args)
    is recognized by MediaWiki, use the returned name; if not, then use the value that
        local text = name(args)
    was provided with the language parameter.
        local loc = args.loc
     
        local page
    When |language= contains a recognized language (either code or name), the page is
        local pages = args.pp or args.pages
    assigned to the category for that code: Category:Norwegian-language sources (no).
        if pages == nil or pages == '' then
    For valid three-character code languages, the page is assigned to the single category
            page = args.p or args.page;
    for '639-2' codes: Category:CS1 ISO 639-2 language sources.
        end  
     
        if nil == loc then loc = "" else loc = " " .. loc end
    Languages that are the same as the local wiki are not categorized. MediaWiki does
        if ( page ~= nil ) then
    not recognize three-character equivalents of two-character codes: code 'ar' is
            local pagesep = config.PageSep or ", p. "
    recognized but code 'ara' is not.
            loc = loc .. pagesep .. page
     
        end
    This function supports multiple languages in the form |language=nb, French, th
        if ( pages ~= nil ) then
    where the language names or codes are separated from each other by commas with
            local pagessep = config.PagesSep or ", pp. "
    optional space characters.
            loc = loc .. pagessep .. pages
     
        end      
    ]]
        local pagename = args.pagename or ""
     
        local ps = args.Postscript or ""
    local function language_parameter (lang)
        return LB .. "[[" .. pagename .. "#" .. anchor .. "|" .. text .. "]]" .. loc .. RB .. ps
    local code; -- the two- or three-character language code
    local name; -- the language name
    local language_list = {}; -- table of language names to be rendered
    local names_table = {}; -- table made from the value assigned to |language=
     
    local this_wiki_name = mw.language.fetchLanguageName (cfg.this_wiki_code, cfg.this_wiki_code); -- get this wiki's language name
     
    names_table = mw.text.split (lang, '%s*,%s*'); -- names should be a comma separated list
     
    for _, lang in ipairs (names_table) do -- reuse lang
    name = cfg.lang_code_remap[lang:lower()]; -- first see if this is a code that is not supported by MediaWiki but is in remap
     
    if name then -- there was a remapped code so
    if not lang:match ('^%a%a%a?%-x%-%a+$') then -- if not a private IETF tag
    lang = lang:gsub ('^(%a%a%a?)%-.*', '%1'); -- strip IETF tags from code
    end
    else
    lang = lang:gsub ('^(%a%a%a?)%-.*', '%1'); -- strip any IETF-like tags from code
    if 2 == lang:len() or 3 == lang:len() then -- if two-or three-character code
    name = mw.language.fetchLanguageName (lang:lower(), cfg.this_wiki_code); -- get language name if |language= is a proper code
    end
    end
     
    if utilities.is_set (name) then -- if |language= specified a valid code
    code = lang:lower(); -- save it
    else
    name, code = get_iso639_code (lang, cfg.this_wiki_code); -- attempt to get code from name (assign name here so that we are sure of proper capitalization)
    end
    if utilities.is_set (code) then -- only 2- or 3-character codes
    name = cfg.lang_code_remap[code] or name; -- override wikimedia when they misuse language codes/names
     
    if cfg.this_wiki_code ~= code then -- when the language is not the same as this wiki's language
    if 2 == code:len() then -- and is a two-character code
    utilities.add_prop_cat ('foreign_lang_source' .. code, {name, code}); -- categorize it; code appended to allow for multiple language categorization
    else -- or is a recognized language (but has a three-character code)
    utilities.add_prop_cat ('foreign_lang_source_2' .. code, {code}); -- categorize it differently TODO: support multiple three-character code categories per cs1|2 template
    end
    elseif cfg.local_lang_cat_enable then -- when the language and this wiki's language are the same and categorization is enabled
    utilities.add_prop_cat ('local_lang_source', {name, code}); -- categorize it
    end
    else
    utilities.set_message ('maint_unknown_lang'); -- add maint category if not already added
    end
    table.insert (language_list, name);
    name = ''; -- so we can reuse it
    end
    name = utilities.make_sep_list (#language_list, language_list);
     
    if this_wiki_name == name then
    return ''; -- if one language and that language is this wiki's return an empty string (no annotation)
    end
    return (" " .. wrap_msg ('language', name)); -- otherwise wrap with '(in ...)'
    --[[ TODO: should only return blank or name rather than full list
    so we can clean up the bunched parenthetical elements Language, Type, Format
    ]]
    end
    end


    function extractauthor(args, i)
    --[[-----------------------< S E T _ C S _ S T Y L E >--------------------------
        local last = args["author" .. i .. "-last"] or args["author-last" .. i] or args["last" .. i] or args["surname" .. i] or args["Author" .. i] or args["author" .. i]
    Gets the default CS style configuration for the given mode.
        if ( last and "" < last ) then -- just in case someone passed in an empty parameter
    Returns default separator and either postscript as passed in or the default.
            return {
    In CS1, the default postscript and separator are '.'.
                last = last,
    In CS2, the default postscript is the empty string and the default separator is ','.
                first = args["author" .. i .. "-first"] or args["author-first" .. i] or args["first" .. i] or args["given" .. i],
    ]]
                link = args["author" .. i .. "-link"] or args["author-link" .. i] or args["author" .. i .. "link"] or args["authorlink" .. i],
    local function set_cs_style (postscript, mode)
                mask = args["author" .. i .. "-mask"] or args["author-mask" .. i] or args["author" .. i .. "mask"] or args["authormask" .. i]
    if utilities.is_set(postscript) then
            }
    -- emit a maintenance message if user postscript is the default cs1 postscript
        else
    -- we catch the opposite case for cs2 in set_style
            return nil
    if mode == 'cs1' and postscript == cfg.presentation['ps_' .. mode] then
        end
    utilities.set_message ('maint_postscript');
    end
    else
    postscript = cfg.presentation['ps_' .. mode];
    end
    return cfg.presentation['sep_' .. mode], postscript;
    end
    end


    function extracteditor(args, i)
    --[[--------------------------< S E T _ S T Y L E >-----------------------------
        local last = args["editor" .. i .. "-last"] or args["editor-last" .. i] or args["EditorSurname" .. i] or args["Editor" .. i] or args["editor" .. i]
    Sets the separator and postscript styles. Checks the |mode= first and the
        if ( last and "" < last ) then -- just in case someone passed in an empty parameter
    #invoke CitationClass second. Removes the postscript if postscript == none.
            return {
    ]]
                last = last,
    local function set_style (mode, postscript, cite_class)
                first = args["editor" .. i .. "-first"] or args["editor-first" .. i] or args["EditorGiven" .. i],
    local sep;
                link = args["editor" .. i .. "-link"] or args["editor-link" .. i] or args["editor" .. i .. "link"] or args["editorlink" .. i],
    if 'cs2' == mode then
                mask = args["editor" .. i .. "-mask"] or args["editor-mask" .. i] or args["editor" .. i .. "mask"] or args["editormask" .. i]
    sep, postscript = set_cs_style (postscript, 'cs2');
            }
    elseif 'cs1' == mode then
        else
    sep, postscript = set_cs_style (postscript, 'cs1');
            return nil
    elseif 'citation' == cite_class then
        end
    sep, postscript = set_cs_style (postscript, 'cs2');
    else
    sep, postscript = set_cs_style (postscript, 'cs1');
    end
     
    if cfg.keywords_xlate[postscript:lower()] == 'none' then
    -- emit a maintenance message if user postscript is the default cs2 postscript
    -- we catch the opposite case for cs1 in set_cs_style
    if 'cs2' == mode or 'citation' == cite_class then
    utilities.set_message ('maint_postscript');
    end
    postscript = '';
    end
    return sep, postscript
    end
    end


    function citation0(frame, args)
    --[=[-------------------------< I S _ P D F >-----------------------------------
        local config = {};
        for k, v in pairs( frame.args ) do -- the arguments passed BY the template, in the wikitext of the template itself
            config[k] = v;
        end


        --------------------------------------------------- Get parameters   
    Determines if a URL has the file extension that is one of the PDF file extensions
        local PPrefix = config.PPrefix or "p.&nbsp;"
    used by [[MediaWiki:Common.css]] when applying the PDF icon to external links.
        local PPPrefix = config.PPPrefix or "pp.&nbsp;"
        if ( nil ~= args.nopp ) then PPPrefix = "" PPrefix = "" end
       
        -- Transfer unnumbered arguments to numbered arguments if necessary.
        args["author1"] = args.author1 or args.author or args.authors
        args["author1-last"] = args["author1-last"] or args["author-last"] or args["last"]
        args["author1-first"] = args["author1-first"] or args["author-first"]
          or args.first or args.first1 or args.given or args.given1
        args["author1-link"] = args["author1-link"] or args["author-link"]
        args["author1-mask"] = args["author1-mask"] or args["author-mask"]
        args["author1link"] = args["author1link"] or args["authorlink"]   
        args["editor1"] = args["editor1"] or args["editor"]
        args["editor1-last"] = args["editor1-last"] or args["editor-last"]
        args["editor1-first"] = args["editor1-first"] or args["editor-first"]
        args["editor1-link"] = args["editor1-link"] or args["editor-link"]
        args["editor1-mask"] = args["editor1-mask"] or args["editor-mask"]
        args["editor1link"] = args["editor1link"] or args["editorlink"]   


        -- Pick out the relevant fields from the arguments.  Different citation templates define different field names for the same underlying things.   
    returns true if file extension is one of the recognized extensions, else false
        local Authors = args.authors
        local i
        local a = {}
        i = 1
        while true do
            a[i] = extractauthor(args, i)
            if ( nil == a[i]) then break end
            i = i + 1
        end
        local Coauthors = args.coauthors or args.coauthor
        local Others = args.others
        local EditorMask = args.editormask or args["editor-mask"]
        local EditorFormat = args["editor-format"] or args.editorformat
        local Editors = args.editors
        local e = {}
        i = 1
        while true do
            e[i] = extracteditor(args, i)
            if ( nil == e[i]) then break end
            i = i + 1
        end
        local Year = args.year
        local PublicationDate = args.publicationdate or args["publication-date"]
        local OrigYear = args.origyear
        local Date = args.date
        local LayDate = args.laydate
        ------------------------------------------------- Get title data
        local Title = args.title or args.encyclopaedia or args.encyclopedia or args.dictionary
        local BookTitle = args.booktitle
        local Conference = args.conference
        local TransTitle = args.trans_title
        local TitleNote = args.department
        local TitleLink = args.titlelink or args.episodelink
        local Chapter = args.chapter or args.contribution or args.entry
        local ChapterLink = args.chapterlink
        local TransChapter = args["trans-chapter"] or args.trans_chapter
        local TitleType = args.type
        local ArchiveURL = args["archive-url"] or args.archiveurl
        local URL = args.url
        local ChapterURL = args["chapter-url"] or args.chapterurl
        local ConferenceURL = args["conference-url"] or args.conferenceurl
        local Periodical = args.journal or args.newspaper or args.magazine or args.work or args.periodical or args.encyclopedia or args.encyclopaedia
        if ( config.CitationClass == "encyclopaedia" ) then
            if ( args.article and args.article ~= "") then
                if ( Title and Title ~= "") then Periodical = Title end
                Chapter = args.article
                TransChapter = TransTitle
                Title = ""           
            elseif ( Chapter == nil or Chapter == '' ) then
                Chapter = Title
                TransChapter = TransTitle
                Title = ""           
            end
            if ( Periodical and Periodical ~= "") then
                if Periodical == Title or Periodical == Chapter then Periodical = '' end
            end
        end
        local Series = args.series or args.version
        local Volume = args.volume
        local Issue = args.issue or args.number
        local Position = nil
        local Page
        local Pages = args.pages
        if Pages == nil or Pages == '' then
            Page = args.page  -- allows Pages to override Page
        else
            Pages = hyphentodash( Pages );
        end


        local PP = args.pp
    ]=]
        local At = args.at
        local Edition = args.edition
        local PublicationPlace = args["publication-place"] or args.publicationplace or args.place or args.location
        local Location = PublicationPlace
        local PublisherName = args.publisher
        local SubscriptionRequired = args.subscription
        local Via = args.via
        local AccessDate = args["access-date"] or args.accessdate
        local ArchiveDate = args["archive-date"] or args.archivedate
        local Agency = args.agency
        local DeadURL = args.deadurl
        local Language = args.language or args["in"]
        local Format = args.format
        local Ref = args.ref or args.Ref
        local ARXIV = args.arxiv or args.ARXIV
        local ASIN = args.asin or args.ASIN
        local ASINTLD = args["ASIN-TLD"] or args["asin-tld"]
        local BIBCODE = args.bibcode or args.BIBCODE
        local DOI = args.doi or args.DOI
        local DoiBroken = args.doi_inactivedate or args.doi_brokendate or args.DoiBroken
        local ID = args.id or args.ID
        local ISBN = args.isbn13 or args.isbn or args.ISBN
        local ISSN = args.issn or args.ISSN
        local JFM = args.jfm or args.JFM
        local JSTOR = args.jstor or args.JSTOR
        local LCCN = args.lccn or args.LCCN
        local MR = args.mr or args.MR
        local OCLC = args.oclc or args.OCLC
        local OL = args.ol or args.OL
        local OSTI = args.osti or args.OSTI
        local PMC = args.pmc or args.PMC
        local PMID = args.pmid or args.PMID
        local RFC = args.rfc or args.RFC
        local SSRN = args.ssrn or args.SSRN
        local ZBL = args.zbl or args.ZBL
        local Quote = args.quote or args.quotation
        local PostScript = args.postscript
        local LaySummary = args.laysummary
        local LaySource = args.laysource
        local Transcript = args.transcript
        local TranscriptURL = args["transcript-url"] or args.transcripturl
        local sepc = args.separator


        if ( config.CitationClass == "journal" ) then
    local function is_pdf (url)
            if (URL == nil or URL == "") then
    return url:match ('%.pdf$') or url:match ('%.PDF$') or
              if (PMC ~= nil and PMC ~="")
    url:match ('%.pdf[%?#]') or url:match ('%.PDF[%?#]') or
                then URL="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC" .. PMC
    url:match ('%.PDF&#035') or url:match ('%.pdf&#035');
                else URL=""
    end
              end
            end
        elseif ( config.CitationClass == "citation" ) then
            sepc = ","
            if ( Ref == nil ) then Ref = "harv" end
        end
        if ( sepc == nil ) then sepc = "." end
        if ( DeadURL == nil ) then DeadURL = "yes" end


        -- At this point fields may be nil if they weren't specified in the template use.  We can use that fact.
     
       
    --[[--------------------------< S T Y L E _ F O R M A T >-----------------------
        -- Account for the oddity that is {{cite conference}}, before generation of COinS data.
     
        if ( BookTitle ) then
    Applies CSS style to |format=, |chapter-format=, etc. Also emits an error message
            Chapter = Title
    if the format parameter does not have a matching URL parameter. If the format parameter
            ChapterLink = TitleLink
    is not set and the URL contains a file extension that is recognized as a PDF document
            TransChapter = TransTitle
    by MediaWiki's commons.css, this code will set the format parameter to (PDF) with
            Title = BookTitle
    the appropriate styling.
            TitleLink = nil
     
            TransTitle = nil
    ]]
        end
     
        -- Account for the oddity that is {{cite episode}}, before generation of COinS data.
    local function style_format (format, url, fmt_param, url_param)
        if config.CitationClass == "episode" then
    if utilities.is_set (format) then
            local AirDate = args.airdate
    format = utilities.wrap_style ('format', format); -- add leading space, parentheses, resize
            local SeriesLink = args.serieslink
    if not utilities.is_set (url) then
            local Season = args.season
    format = format .. ' ' .. utilities.set_message ( 'err_format_missing_url', {fmt_param, url_param} ); -- add an error message
            local SeriesNumber = args.seriesnumber or args.seriesno
    end
            local Network = args.network
    elseif is_pdf (url) then -- format is not set so if URL is a PDF file then
            local Station = args.station
    format = utilities.wrap_style ('format', 'PDF'); -- set format to PDF
            local s = {}
            if Issue ~= nil then table.insert(s, "episode " .. Issue) Issue = nil end
            if Season ~= nil then table.insert(s, "season " .. Season) end
            if SeriesNumber ~= nil then table.insert(s, "series " .. SeriesNumber) end
            local n = {}
            if Network ~= nil then table.insert(n, Network) end
            if Station ~= nil then table.insert(n, Station) end
            Date = Date or AirDate
            Chapter = Title
            ChapterLink = TitleLink
            TransChapter = TransTitle
            Title = Series
            TitleLink = SeriesLink
            TransTitle = nil
            local Sep = args["series-separator"] or args["separator"] or ". "
            Series = table.concat(s, Sep)
            ID = table.concat(n, Sep)
        end
       
        -- These data form a COinS tag (see <http://ocoins.info/>) which allows automated tools to parse the citation information.
        local OCinSdata = {} -- COinS metadata excluding id, bibcode, doi, etc.
        local ctx_ver = "Z39.88-2004"
        OCinSdata.rft_val_fmt = "info:ofi/fmt:kev:mtx:book"
        if ( nil ~= Periodical ) then
            OCinSdata.rft_val_fmt = "info:ofi/fmt:kev:mtx:journal"
            OCinSdata["rft.genre"] = "article"
            OCinSdata["rft.jtitle"] = Periodical
            if ( nil ~= Title ) then OCinSdata["rft.atitle"] = Title end
        end
        if ( nil ~= Chapter and "" ~= Chapter) then
            OCinSdata.rft_val_fmt = "info:ofi/fmt:kev:mtx:book"
            OCinSdata["rft.genre"] = "bookitem"
            OCinSdata["rft.btitle"] = Chapter
            if ( nil ~= Title ) then OCinSdata["rft.atitle"] = Title end
        else
            OCinSdata["rft.genre"] = "book"
        if ( nil ~= Title ) then OCinSdata["rft.btitle"] = Title end
        end
        OCinSdata["rft.place"] = PublicationPlace
        OCinSdata["rft.date"] = Date or Year or PublicationDate
        OCinSdata["rft.series"] = Series
        OCinSdata["rft.volume"] = Volume
        OCinSdata["rft.issue"] = Issue
        OCinSdata["rft.pages"] = Page or Pages or At
        OCinSdata["rft.edition"] = Edition
        OCinSdata["rft.pub"] = PublisherName
        OCinSdata["rft.isbn"] = ISBN
        OCinSdata["rft.issn"] = ISSN
        OCinSdata["rft.jfm"] = JFM
        OCinSdata["rft.jstor"] = JSTOR
        OCinSdata["rft.lccn"] = LCCN
        OCinSdata["rft.mr"] = MR
        OCinSdata.rft_id = URL or ChapterURL
        if ( nil ~= a[1] and nil ~= a[1].last) then
        local last = a[1].last
    local first = a[1].first
    OCinSdata["rft.aulast"] = last
            if ( nil ~= first ) then  
        OCinSdata["rft.aufirst"] = first
        OCinSdata["rft.au"] = last .. (args.NameSep or ", ") .. first
    else
    else
        OCinSdata["rft.au"] = last
    format = ''; -- empty string for concatenation
            end
    end
        end
    return format;
        local OCinSids = {} -- COinS data only for id, bibcode, doi, pmid, etc.
    end
        OCinSids["info:arxiv"] = ARXIV
        OCinSids["info:asin"] = ASIN
        OCinSids["info:bibcode"] = BIBCODE
        OCinSids["info:doi"] = DOI
        OCinSids["info:oclcnum"] = OCLC
        OCinSids["info:olnum"] = OL
        OCinSids["info:osti"] = OSTI
        OCinSids["info:pmc"] = PMC
        OCinSids["info:pmid"] = PMID
        OCinSids["info:rfc"] = RFC
        OCinSids["info:ssrn"] = SSRN
        OCinSids["info:zbl"] = ZBL
        local OCinStitle = "ctx_ver=" .. ctx_ver  -- such as "Z39.88-2004"
        for name,value in pairs(OCinSids) do
            OCinStitle = OCinStitle .. "&rft_id=" .. z.mw.url.encode(name .. "/" .. value)
        end
        for name,value in pairs(OCinSdata) do
            OCinStitle = OCinStitle .. "&" .. name .. "=" .. z.mw.url.encode(value)
        end
        OCinStitle = OCinStitle .. "&rfr_id=info:sid/en.wikipedia.org:"
          .. config.fullpagename  -- end COinS data by page's non-encoded pagename


        -- Now perform various field substitutions.
        -- We also add leading spaces and surrounding markup and punctuation to the various parts of the citation, but only when they are non-nil.
        if ( Authors == nil ) then
            local AuthorNameSep = args["author-name-separator"] or args["name-separator"] or "&#44;"
            AuthorNameSep = AuthorNameSep .. " "
            local AuthorSep = args["author-separator"] or args["separator"] or "&#59;"
            AuthorSep = AuthorSep .. " "
            local AuthorFormat = args["author-format"] or args.authorformat
            local AuthorMaximum = tonumber(args["display-authors"] or args.displayauthors) or 8
            local control = { sep = AuthorSep, namesep = AuthorNameSep, format = AuthorFormat, maximum = AuthorMaximum }
            Authors = listpeople(control, a)
        end
        local EditorCount
        if ( Editors == nil ) then
            local EditorNameSep = args["editor-name-separator"] or args["name-separator"] or "&#44; "
            local EditorSep = args["editor-separator"] or args["separator"] or "&#59; "
            local EditorFormat = args["editor-format"] or args.editorformat
            local EditorMaximum = tonumber(args["display-editors"] or args.displayeditors) or 3
            local control = { sep = EditorSep, namesep = EditorNameSep, format = EditorFormat, maximum = EditorMaximum }
            Editors, EditorCount = listpeople(control, e)
        else
            EditorCount = 1;
        end
        if ( Date == nil or Date == "") then
    --  there's something hinky with how this adds dashes to perfectly-good free-standing years
    --[[        Date = Year
            if ( Date ~= nil ) then
                local Month = args.month
                if ( Month == nil ) then
                    local Began = args.began
                    local Ended = args.ended
                    if Began ~= nil and Ended ~= nil then
                        Month = Began .. "&ndash;" .. Ended
                    else
                        Month = "&ndash;"
                    end
                end
                Date = Month .. " " .. Date
                local Day = args.day
                if ( Day ~= nil ) then Date = Day .. " " .. Date end
            end
    ]] -- so let's use the original version for now
            Date = Year
            if ( Date ~= nil and Date ~="") then
                local Month = args.month
                if ( Month ~= nil and Month ~= "") then
                    Date = Month .. " " .. Date
                    local Day = args.day
                    if ( Day ~= nil ) then Date = Day .. " " .. Date end
                    else Month = ""
                end
                else Date = ""
            end
        end
        if ( PublicationDate == Date or PublicationDate == Year ) then PublicationDate = nil end
        if( (Date == nil or Date == "") and PublicationDate ~= nil ) then
            Date = PublicationDate;
            PublicationDate = nil;
        end   


        -- Captures the value for Date prior to adding parens or other textual transformations
    --[[---------------------< G E T _ D I S P L A Y _ N A M E S >------------------
        local DateIn = Date


        if ( Format ~= nil and Format ~="" ) then
    Returns a number that defines the number of names displayed for author and editor
            Format = " (" .. Format .. ")" else Format = "" end
    name lists and a Boolean flag to indicate when et al. should be appended to the name list.
        if ( ArchiveURL and "" < ArchiveURL ) then
            if ( DeadURL ~= "no" ) then
              local temp = URL
              URL = ArchiveURL
            end
        end
        if ( TransTitle and "" < TransTitle ) then TransTitle = " [" .. TransTitle .. "&#93;" else TransTitle = "" end
        if ( TransChapter and "" < TransChapter ) then TransChapter = " [" .. TransChapter .. "&#93;" else TransChapter = "" end
        if ( Chapter and "" < Chapter ) then
            if ( ChapterLink and "" < ChapterLink ) then Chapter = "[[" .. ChapterLink .. "|" .. Chapter .. "]]" end
            if ( Periodical and "" < Periodical
                and config.CitationClass ~= "encyclopaedia"
            ) then
                Chapter = "''" .. safeforitalics(Chapter) .. "''"
            else
                Chapter = "\"" .. Chapter .. "\""
            end
            Chapter = Chapter .. TransChapter
            if ( ChapterLink == nil ) then
                if ( ChapterURL and "" < ChapterURL ) then
                    Chapter = "[" .. ChapterURL .. " " .. safeforurl( Chapter )  .. "]"
                elseif ( URL and "" < URL ) then
                    Chapter = "[" .. URL .. " " .. safeforurl( Chapter ) .. "]" .. Format
                    URL = nil
                    Format = ""
                end
            end
            Chapter = Chapter .. sepc .. " " -- with end-space
        else
            Chapter = ""
        end
        if ( Title and "" < Title ) then
            if ( TitleLink and "" < TitleLink ) then
                Title = "[[" .. TitleLink .. "|" .. Title .. "]]" end
            if ( Periodical and "" < Periodical ) then
                Title = "\"" .. Title .. "\""
            elseif ( config.CitationClass == "web"
                  or config.CitationClass == "news" ) then
                Title = "\"" .. Title .. "\""
            else
                Title = "''" .. safeforitalics(Title) .. "''"
            end
            Title = Title .. TransTitle
            if ( TitleLink == nil and URL and "" < URL ) then
                Title = "[" .. URL .. " " .. safeforurl( Title ) .. "]" .. Format
                URL = nil
                Format = ''
            end
        else
            Title = ""
        end
        if ( Conference ~= nil and Conference ~="" ) then
            if ( ConferenceURL ~= nil ) then
                Conference = "[" .. ConferenceURL .. " " .. safeforurl( Conference ) .. "]"
            end
            Conference = " " .. Conference
        else
            Conference = ""
        end
        if ( nil ~= Position or nil ~= Page or nil ~= Pages ) then At = nil end
        if ( nil == Position and "" ~= Position ) then
            local Minutes = args.minutes
            if ( nil ~= Minutes ) then
                Position = " " .. Minutes .. " minutes in"
            else
                local Time = args.time
                if ( nil ~= Time ) then
                    local TimeCaption = args.timecaption or "Event occurs at"
                    Position = " " .. TimeCaption .. " " .. Time
                else
                    Position = ""
                end
            end
        else
            Position = " " .. Position
        end
        if ( nil == Page or "" == Page ) then
            Page = ""
        elseif ( Periodical ~= nil and Periodical ~= "" and
                config.CitationClass ~= "encyclopaedia" and
                config.CitationClass ~= "web" and
                config.CitationClass ~= "book" and
                config.CitationClass ~= "news") then
            Page = ": " .. Page
        else
            Page = sepc .." " .. PPrefix .. Page
        end
        if ( nil == Pages or "" == Pages) then
            Pages = ""
        elseif ( Periodical ~= nil and Periodical ~= "" and
                config.CitationClass ~= "encyclopaedia" and
                config.CitationClass ~= "web" and
                config.CitationClass ~= "book" and
                config.CitationClass ~= "news") then
            Pages = ": " .. Pages
        else
            if ( tonumber(Pages) ~= nil ) then
              Pages = sepc .." " .. PPrefix .. Pages
            else Pages = sepc .." " .. PPPrefix .. Pages
            end
        end
        if ( At ~= nil and At ~="") then At = sepc .. " " .. At
        else At = "" end
        if ( Coauthors == nil ) then Coauthors = "" end
        if ( Others ~= nil and Others ~="" ) then
            Others = sepc .. " " .. Others else Others = "" end
        if ( TitleType ~= nil and TitleType ~="" ) then
            TitleType = " (" .. TitleType .. ")" else TitleType = "" end
        if ( TitleNote ~= nil and TitleNote ~="" ) then
            TitleNote = sepc .. " " .. TitleNote else TitleNote = "" end
        if ( PublicationPlace ~= nil and PublicationPlace ~="" ) then
            PublicationPlace = PublicationPlace .. ": "
            else PublicationPlace = "" end
        if ( Language ~= nil and Language ~="" ) then
            Language = " (in " .. Language .. ")" else Language = "" end
        if ( Edition ~= nil and Edition ~="" ) then
            Edition = " (" .. Edition .. " ed.)" else Edition = "" end
        if ( Volume ~= nil and Volume ~="" )
        then
            if ( string.len(Volume) > 4 )
              then Volume = sepc .." " .. Volume
              else Volume = " <b>" .. Volume .. "</b>"
            end
        else Volume = "" end
        if ( Issue ~= nil and Issue ~="" ) then
            Issue = " (" .. Issue .. ")" else Issue = "" end
        if ( Series ~= nil and Series ~="" ) then
            Series = sepc .. " " .. Series else Series = "" end
        if ( OrigYear ~= nil and OrigYear ~="" ) then
            OrigYear = " [" .. OrigYear .. "]" else OrigYear = "" end
        if ( Agency ~= nil and Agency ~="" ) then
            Agency = sepc .. " " .. Agency else Agency = "" end
        ------------------------------------ totally unrelated data
        if ( Date ~= nil ) then Date = Date else Date = "" end
        if ( Via ~= nil and Via ~="" ) then
            Via = " &mdash; via " .. Via else Via = "" end
        if ( AccessDate ~= nil and AccessDate ~="" )
        then local retrv_text = " retrieved "
            if (sepc == ".") then retrv_text = " Retrieved " end
            AccessDate = '<span class="reference-accessdate">'
            .. sepc .. retrv_text .. AccessDate .. '</span>'
        else AccessDate = "" end
        if ( SubscriptionRequired ~= nil and
            SubscriptionRequired ~= "" ) then
            SubscriptionRequired = sepc .. " " .. z.mw.text.tag({name="span", contents="(subscription required)", params={style="font-size:0.95em; font-size: 90%; color: #555"}})
        else
            SubscriptionRequired = ""
        end
        if ( ARXIV ~= nil and ARXIV ~= "" ) then
            ARXIV = sepc .. " " .. externallinkid(frame, {label="arXiv",link="arXiv",prefix="http://arxiv.org/abs/",id=ARXIV,separator=":",encode=false}) else ARXIV = "" end
        if ( ASIN ~= nil and ASIN ~= "" ) then
            ASIN = sepc .. " " .. amazon(frame, ASIN, ASINTLD) else ASIN = "" end
        if ( BIBCODE ~= nil and BIBCODE ~= "" ) then
            BIBCODE = sepc .. " " .. externallinkid(frame, {label="Bibcode",link="Bibcode",prefix="http://adsabs.harvard.edu/abs/",id=BIBCODE,separator=":"}) else BIBCODE = "" end
        if ( DOI ~= nil and DOI ~= "" ) then
          DOI = sepc .. " " .. doi(frame, DOI, DoiBroken) else DOI = "" end
        if ( ID ~= nil and ID ~="") then ID = sepc .." ".. ID else ID="" end
        if ( ISBN ~= nil and ISBN ~= "") then
            ISBN = sepc .. " " .. internallinkid(frame, {label="ISBN",link="International Standard Book Number",prefix="Special:BookSources/",id=ISBN}) else ISBN = "" end
        if ( ISSN ~= nil and ISSN ~="" ) then
            ISSN = sepc .. " " .. externallinkid(frame, {label="ISSN",link="International Standard Serial Number",prefix="//www.worldcat.org/issn/",id=ISSN,encode=false}) else ISSN = "" end
        if ( JFM ~= nil and JFM ~="" ) then
            JFM = sepc .." " .. externallinkid(frame, {label="JFM",link="Jahrbuch über die Fortschritte der Mathematik",prefix="http://www.zentralblatt-math.org/zmath/en/search/?format=complete&q=an:",id=JFM}) else JFM = "" end
        if ( JSTOR ~= nil and JSTOR ~="") then
            JSTOR = sepc .." " .. externallinkid(frame, {label="JSTOR",link="JSTOR",prefix="http://www.jstor.org/stable/",id=JSTOR}) else JSTOR = "" end
        if ( LCCN ~= nil and LCCN ~="" ) then
            LCCN = sepc .." " .. externallinkid(frame, {label="LCCN",link="Library of Congress Control Number",prefix="http://lccn.loc.gov/",id=LCCN,encode=false}) else LCCN = "" end
        if ( MR ~= nil and MR ~="" ) then
            MR = sepc .." " .. externallinkid(frame, {label="MR",link="Mathematical Reviews",prefix="http://www.ams.org/mathscinet-getitem?mr=",id=MR}) else MR = "" end
        if ( OCLC ~= nil and OCLC ~="") then
            OCLC = sepc .." " .. externallinkid(frame, {label="OCLC",link="OCLC",prefix="//www.worldcat.org/oclc/",id=OCLC}) else OCLC = "" end
        if ( OL ~= nil and OL ~="") then
            OL = sepc .." " .. openlibrary(frame, OL) else OL = "" end
        if ( OSTI ~= nil and OSTI ~="") then
            OSTI = sepc .." " .. externallinkid(frame, {label="OSTI",link="Office of Scientific and Technical Information",prefix="http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=",id=OSTI}) else OSTI = "" end
        if ( PMC ~= nil and PMC ~="") then
            PMC = sepc .." " .. externallinkid(frame, {label="PMC",link="PubMed Central",prefix="//www.ncbi.nlm.nih.gov/pmc/articles/PMC",suffix=" ",id=PMC}) else PMC = "" end
        if ( PMID ~= nil and PMID ~="") then
            PMID = sepc .." " .. externallinkid(frame, {label="PMID",link="PubMed Identifier",prefix="//www.ncbi.nlm.nih.gov/pubmed/",id=PMID,encode=false}) else PMID = "" end
        if ( RFC ~= nil and RFC ~="") then
            RFC = sepc .." " .. externallinkid(frame, {label="RFC",link="Request for Comments",prefix="//tools.ietf.org/html/rfc",id=RFC}) else RFC = "" end
        if ( SSRN ~= nil and SSRN ~="") then
            SSRN = sepc .." " .. externallinkid(frame, {label="SSRN",link="Social Science Research Network",prefix="http://ssrn.com/abstract=",id=SSRN}) else SSRN = "" end
        if ( URL ~= nil and URL ~="") then
          URL = " " .. url(frame, URL)
        else
          URL = ""
        end
        if ( ZBL ~= nil and ZBL ~="") then
            ZBL = sepc .." " .. externallinkid(frame, {label="Zbl",link="Zentralblatt MATH",prefix="http://www.zentralblatt-math.org/zmath/en/search/?format=complete&q=an:",id=ZBL}) else ZBL = "" end
        if ( Quote and Quote ~="" ) then
            if Quote:sub(1,1) == '"' and Quote:sub(-1,-1) == '"' then
                Quote = Quote:sub(2,-2);
            end
           
            Quote = sepc .." \"" .. Quote .. "\""
            PostScript = ""
        else
            if ( PostScript == nil) then PostScript = "" end
            Quote = ""
        end
        local Archived
        if ( nil ~= ArchiveURL and "" ~= ArchiveURL ) then
            if ( ArchiveDate ~= nil and ArchiveDate ~="" ) then
                ArchiveDate = " " .. ArchiveDate
            else ArchiveDate = "" end
            local arch_text = " archived"
            if (sepc == ".") then arch_text = " Archived" end
            if ( "no" == DeadURL ) then
                Archived = sepc .. " [" .. ArchiveURL .. arch_text .. "] from the original on" .. ArchiveDate
            else
                Archived = sepc .. arch_text .. " from [" .. args.url .. " the original] on" .. ArchiveDate
            end
        else
            Archived = ""
        end
        local Lay
        if ( nil ~= LaySummary and "" ~= LaySummary ) then
            if ( LayDate ~= nil ) then LayDate = " (" .. LayDate .. ")" else LayDate = "" end
            if ( LaySource ~= nil ) then
                LaySource = " &ndash; ''" .. safeforitalics(LaySource) .. "''"
            else
                LaySource = ""
            end
            Lay = " [" .. LaySummary .. " lay summary]" .. LaySource .. LayDate
        else
            Lay = ""
        end
        if ( nil ~= Transcript and "" ~= Transcript ) then
            if ( TranscriptURL ~= nil ) then Transcript = "[" .. TranscriptURL .. Transcript .. "]" end
        else
            Transcript = ""
        end
        local Publisher = ""
        if ( Periodical and Periodical ~= "" and
            config.CitationClass ~= "encyclopaedia" and
            config.CitationClass ~= "web" ) then
            if ( PublicationDate and PublicationDate ~="" )
                then PublicationDate = " " .. PublicationDate
                else PublicationDate = "" end
            if ( PublisherName and PublisherName ~="" ) then
                Publisher = " (" .. PublicationPlace .. PublisherName .. PublicationDate .. ")"
            else
                if (Location ~= nil and Location ~= '') then Publisher= " (" .. Location .. ")"
                else Publisher = "" end
            end
        else
            if ( PublicationDate and PublicationDate ~="" ) then
                PublicationDate = " (published " .. PublicationDate .. ")"
                else PublicationDate = "" end
            if ( PublisherName and PublisherName ~="" ) then
                Publisher = sepc .. " " .. PublicationPlace .. PublisherName .. PublicationDate
            else
                if (Location ~= nil and Location ~= '') then Publisher= sepc .. " " .. Location
                else Publisher = "" end
            end
        end
        -- Several of the above rely upon detecting this as nil, so do it last.
        if ( Periodical ~= nil and Periodical ~="" ) then
            if ( Title and Title ~= "") then
                Periodical = sepc .. " ''" .. safeforitalics(Periodical) .. "''"
            else
                Periodical = "''" .. safeforitalics(Periodical) .. "''"
            end
        else Periodical = "" end


        -- Piece all bits together at last.  Here, all should be non-nil.
    When the value assigned to |display-xxxxors= is a number greater than or equal to zero,
        -- We build things this way because it is more efficient in LUA
    return the number and the previous state of the 'etal' flag (false by default
        -- not to keep reassigning to the same string variable over and over.
    but may have been set to true if the name list contains some variant of the text 'et al.').


        local tcommon
    When the value assigned to |display-xxxxors= is the keyword 'etal', return a number
        if ( config.CitationClass == "journal" )
    that is one greater than the number of authors in the list and set the 'etal' flag true.
        then tcommon = safejoin( {Title, TitleNote, Format, TitleType, Conference, Periodical, Series, Language, Edition, Publisher, Agency, Others, Volume, Issue, Position }, sepc );
    This will cause the list_people() to display all of the names in the name list followed by 'et al.'
        elseif ( config.CitationClass == "citation" )
        then tcommon = safejoin( {Title, TitleNote, Format, TitleType, Conference, Periodical, Series, Language, Volume, Issue, Edition, Publisher, Agency, Others, Position}, sepc );
        else tcommon = safejoin( {Title, TitleNote, Series, Format, TitleType, Conference, Periodical, Language, Volume, Issue, Edition, Publisher, Agency, Others, Position}, sepc );
        end
        -- DEBUG: tcommon = "/Title="..Title .. "/TitleType="..TitleType .. "/TitleNote="..TitleNote .. "/Format="..Format .. "/Edition="..Edition .. "/Language="..Language .. "/Conference="..Conference .. "/Periodical="..Periodical .. "/Series="..Series .. "/Volume="..Volume .. "/Issue="..Issue .. "/Position="..Position


        local idcommon = safejoin( { ARXIV, ASIN, BIBCODE, DOI, ISBN, ISSN, JFM, JSTOR, LCCN, MR, OCLC, OL, OSTI, PMC, PMID, RFC, SSRN, URL, ZBL, ID, Archived, AccessDate, Via, SubscriptionRequired, Lay, Quote, PostScript }, sepc );
    In all other cases, returns nil and the previous state of the 'etal' flag.
        local enddot = "."
        if (Quote ~= "") then enddot = "" end
        if ( config.CitationClass == "citation") then enddot = "" end
        idcommon = safejoin( { idcommon, enddot }, sepc )


        if ( config.CitationClass == "encyclopaedia" ) then
    inputs:
            Chapter = Chapter
    max: A['DisplayAuthors'] or A['DisplayEditors']; a number or some flavor of etal
        end
    count: #a or #e
    list_name: 'authors' or 'editors'
    etal: author_etal or editor_etal


        local text
    ]]
        local pgtext = Page .. Pages .. At
        if ( "" ~= Authors ) then
            if (Coauthors ~= "")
              then Authors = Authors .. "; " .. Coauthors
            end
            if ( "" ~= Date )
              then Date = " ("..Date..")" .. OrigYear .. sepc .. " "
              else
                if ( string.sub(Authors,-1,-1) == sepc) --check end character
                  then Authors = Authors .. " "
                  else Authors = Authors .. sepc .. " "
                end
            end
            if ( "" ~= Editors) then
                local in_text = " in "
                if (sepc == '.') then in_text = " In " end
                if (string.sub(Editors,-1,-1) == sepc)
                    then Editors = in_text .. Editors .. " "
                    else Editors = in_text .. Editors .. sepc .. " "
                end
            end
            text = Authors .. Date .. Chapter .. Editors .. tcommon
            text = safejoin( {text, pgtext, idcommon}, sepc );
        elseif ( "" ~= Editors) then
            if ( "" ~= Date ) then
                if EditorCount <= 1 then
                    Editors = Editors .. ", ed."
                else
                    Editors = Editors .. ", eds."
                end               
                Date = " (" .. Date ..")" .. OrigYear .. sepc .. " "
            else
                if EditorCount <= 1 then
                    Editors = Editors .. " (ed.)" .. sepc .. " "
                else
                    Editors = Editors .. " (eds.)" .. sepc .. " "
                end               
            end
            text = Editors .. Date .. Chapter .. tcommon
            text = safejoin( {text, pgtext, idcommon}, sepc );
        else
            if ( "" ~= Date ) then
                if ( string.sub(tcommon,-1,-1) ~= sepc )
                  then Date = sepc .." " .. Date
                  else Date = " " .. Date
                end
            end -- endif ""~=Date
            text = Chapter .. tcommon .. Date
            text = safejoin( {text, pgtext, idcommon}, sepc );
        end
       
        -- Now enclose the whole thing in a <span/> element
        if ( Year == nil ) then
            if ( DateIn ~= nil and DateIn ~= "" ) then
                Year = selectyear( DateIn )
            elseif( PublicationDate ~= nil and PublicationDate ~= "" ) then
                Year = selectyear( PublicationDate )
            else
                Year = ""
            end       
        end
        local classname = "citation"
        if ( config.CitationClass ~= "citation" )
          then classname = "citation " .. (config.CitationClass or "") end
        local args = { class=classname }
        if ( Ref ~= nil ) then
            local id = Ref
            if ( "harv" == Ref ) then
                local names = {} --table of last names & year
                if ( "" ~= Authors ) then
                    for i,v in ipairs(a) do names[i] = v.last end
                elseif ( "" ~= Editors ) then
                    for i,v in ipairs(e) do names[i] = v.last end
                end
                if ( names[1] == nil ) then
                    names[1] = Year
                elseif ( names[2] == nil ) then
                    names[2] = Year
                elseif ( names[3] == nil ) then
                    names[3] = Year
                elseif ( names[4] == nil ) then
                    names[4] = Year
                else
                    names[5] = Year
                end
                id = anchorid(names)
            end
            args.id = id;
        end
        if ( text:sub(-4,-1) == ".''." ) then --when dot after title
            text = text:sub(1,-2) end --truncate end-dot
        text = z.mw.text.tag({name="span", contents=text, params=args})


        local empty_span = z.mw.text.tag( {name="span", contents="&nbsp;", params={style="display: none;"}} );
    local function get_display_names (max, count, list_name, etal, param)
       
    if utilities.is_set (max) then
        -- Note: Using display: none on then COinS span breaks some clients.
    if 'etal' == max:lower():gsub("[ '%.]", '') then -- the :gsub() portion makes 'etal' from a variety of 'et al.' spellings and stylings
        local OCinS = z.mw.text.tag({name="span", contents=empty_span, params={class="Z3988",title=OCinStitle }})  
    max = count + 1; -- number of authors + 1 so display all author name plus et al.
           
    etal = true; -- overrides value set by extract_names()
        return text .. OCinS
    elseif max:match ('^%d+$') then -- if is a string of numbers
    max = tonumber (max); -- make it a number
    if max >= count then -- if |display-xxxxors= value greater than or equal to number of authors/editors
    table.insert( z.message_tail, {utilities.set_message ('err_disp_name', {param, max}, true)}); -- add error message
    max = nil;
    end
    else -- not a valid keyword or number
    table.insert( z.message_tail, {utilities.set_message ('err_disp_name', {param, max}, true)}); -- add error message
    max = nil; -- unset; as if |display-xxxxors= had not been set
    end
    end
    return max, etal;
    end
    end


    function r0(frame, name, group, page)
     
        if ( name == nil ) then return "" end
    --[[----------< E X T R A _ T E X T _ I N _ P A G E _ C H E C K >---------------
        if ( group == nil ) then group = "" end
     
        local p = ""
    Adds error if |page=, |pages=, |quote-page=, |quote-pages= has what appears to be
        if ( page ~= nil ) then  
    some form of p. or pp. abbreviation in the first characters of the parameter content.
            local contents = ":" .. page
     
            p = z.mw.text.tag({name="sup",contents=contents,params={class="reference",style="white-space:nowrap;"}})
    check page for extraneous p, p., pp, pp., pg, pg. at start of parameter value:
        end
    good pattern: '^P[^%.P%l]' matches when page begins PX or P# but not Px
        return z.mw.text.tag({name="ref",contents="",params={name=name,group=group}}, frame) .. p
          where x and X are letters and # is a digit
    bad pattern:  '^[Pp][PpGg]' matches when page begins pp, pP, Pp, PP, pg, pG, Pg, PG
     
    ]]
     
    local function extra_text_in_page_check (val, name)
    if not val:match (cfg.vol_iss_pg_patterns.good_ppattern) then
    for _, pattern in ipairs (cfg.vol_iss_pg_patterns.bad_ppatterns) do -- spin through the selected sequence table of patterns
    if val:match (pattern) then -- when a match, error so
    table.insert (z.message_tail, {utilities.set_message ('err_extra_text_pages', {name}, true)}); -- add error message
    return; -- and done
    end
    end
    end
    end
    end


    function reflist0(frame, config, args)
     
        local contents = args.refs or ""
    --[[--------------------------< E X T R A _ T E X T _ I N _ V O L _ I S S _ C H E C K >------------------------
        local liststyle = args.liststyle
     
        local count = args[1]
    Adds error if |volume= or |issue= has what appears to be some form of redundant 'type' indicator.
        local width = args.colwidth
     
        local group = args.group or config.default_group
    For |volume=:
        if ( nil == tonumber(count) and nil == width ) then
    'V.', or 'Vol.' (with or without the dot) abbreviations or 'Volume' in the first characters of the parameter
            width = count
    content (all case insensitive). 'V' and 'v' (without the dot) are presumed to be roman numerals so
            count = nil
    are allowed.
        end
     
        if ( nil == liststyle ) then
    For |issue=:
            if ( "upper-alpha" == group or "lower-alpha" == group or "upper-roman" == group or "lower-roman" == group or "upper-greek" == group or "lower-greek" == group ) then
    'No.', 'I.', 'Iss.' (with or without the dot) abbreviations, or 'Issue' in the first characters of the
                liststyle = group
    parameter content (all case insensitive).
            else
                liststyle = config.default_liststyle
    Single character values ('v', 'i', 'n') allowed when not followed by separator character ('.', ':', '=', or
            end
    whitespace character) – param values are trimmed of whitespace by MediaWiki before delivered to the module.
        end
        local params = {}
    <val> is |volume= or |issue= parameter value
        params.class = "reflist"   
    <name> is |volume= or |issue= parameter name for error message
        params.style = z.wikitext.liststyle(liststyle)
    <selector> is 'v' for |volume=, 'i' for |issue=
        if ( nil ~= count ) then      
     
            params.class = params.class .. " references-column-count references-column-count-" .. count
    sets error message on failure; returns nothing
            params.style = params.style .. " " .. z.wikitext.columncountstyle(count)
     
        end   
    ]]
        if ( nil ~= width ) then
     
            params.class = params.class .. " references-column-width"
    local function extra_text_in_vol_iss_check (val, name, selector)
            params.style = params.style .. " " .. z.wikitext.columnwidthstyle(width)
    if not utilities.is_set (val) then
        end
    return;
        local references = z.mw.text.tag({name="references",contents=contents,params={group=group}}, frame)
    end
        return z.mw.text.tag({name="div",contents=references,params=params})
    local patterns = 'v' == selector and cfg.vol_iss_pg_patterns.vpatterns or cfg.vol_iss_pg_patterns.ipatterns;
     
    local handler = 'v' == selector and 'err_extra_text_volume' or 'err_extra_text_issue';
    val = val:lower(); -- force parameter value to lower case
    for _, pattern in ipairs (patterns) do -- spin through the selected sequence table of patterns
    if val:match (pattern) then -- when a match, error so
    table.insert (z.message_tail, {utilities.set_message (handler, {name}, true)}); -- add error message
    return; -- and done
    end
    end
    end
    end


    function refbegin0(frame, config, args)
     
        local liststyle = args.liststyle
    --[=[-------------------------< G E T _ V _ N A M E _ T A B L E >----------------------------------------------
        local indent = args.indent
     
        local indentsize = args.indentsize
    split apart a |vauthors= or |veditors= parameter. This function allows for corporate names, wrapped in doubled
        local count = args[1]
    parentheses to also have commas; in the old version of the code, the doubled parentheses were included in the
        local width = args.colwidth
    rendered citation and in the metadata. Individual author names may be wikilinked
        if ( nil == tonumber(count) and nil == width ) then
     
            width = count
    |vauthors=Jones AB, [[E. B. White|White EB]], ((Black, Brown, and Co.))
            count = nil
     
        end
    ]=]
        if ( nil == liststyle ) then
     
            if ( "upper-alpha" == group or "lower-alpha" == group or "upper-roman" == group or "lower-roman" == group or "upper-greek" == group or "lower-greek" == group ) then
    local function get_v_name_table (vparam, output_table, output_link_table)
                liststyle = group
    local name_table = mw.text.split(vparam, "%s*,%s*"); -- names are separated by commas
            else
    local wl_type, label, link; -- wl_type not used here; just a placeholder
                liststyle = config.default_liststyle
            end
    local i = 1;
        end
        local params = {}
    while name_table[i] do
        params.class = "refbegin"
    if name_table[i]:match ('^%(%(.*[^%)][^%)]$') then -- first segment of corporate with one or more commas; this segment has the opening doubled parentheses
        params.style = z.wikitext.liststyle(liststyle)
    local name = name_table[i];
        if ( nil ~= count ) then      
    i = i + 1; -- bump indexer to next segment
            params.class = params.class .. " references-column-count references-column-count-" .. count
    while name_table[i] do
            params.style = params.style .. " " .. z.wikitext.columncountstyle(count)
    name = name .. ', ' .. name_table[i]; -- concatenate with previous segments
        end   
    if name_table[i]:match ('^.*%)%)$') then -- if this table member has the closing doubled parentheses
        if ( nil ~= width ) then
    break; -- and done reassembling so
            params.class = params.class .. " references-column-width"
    end
            params.style = params.style .. " " .. z.wikitext.columnwidthstyle(width)
    i = i + 1; -- bump indexer
        end
    end
        local dlopen
    table.insert (output_table, name); -- and add corporate name to the output table
        if ( nil ~= indent ) then
    table.insert (output_link_table, ''); -- no wikilink
            dlopen = z.wikitext.OpenHTMLTag({name="dl",params={style="text-indent: -" .. (indentsize or "3.2") .. "em;"}})
    else
        else
    wl_type, label, link = utilities.is_wikilink (name_table[i]); -- wl_type is: 0, no wl (text in label variable); 1, [[D]]; 2, [[L|D]]
            dlopen = ""
    table.insert (output_table, label); -- add this name
        end
    if 1 == wl_type then
        return z.wikitext.OpenHTMLTag({name="div",params=params}) .. dlopen
    table.insert (output_link_table, label); -- simple wikilink [[D]]
    else
    table.insert (output_link_table, link); -- no wikilink or [[L|D]]; add this link if there is one, else empty string
    end
    end
    i = i + 1;
    end
    return output_table;
    end
    end


    function refend0(frame, config, args)
     
        local indent = args.indent
    --[[--------------------------< P A R S E _ V A U T H O R S _ V E D I T O R S >--------------------------------
        local dlclose
     
        if ( nil ~= indent ) then
    This function extracts author / editor names from |vauthors= or |veditors= and finds matching |xxxxor-maskn= and
            dlclose = "</dl>"
    |xxxxor-linkn= in args.  It then returns a table of assembled names just as extract_names() does.
        else
     
            dlclose = ""
    Author / editor names in |vauthors= or |veditors= must be in Vancouver system style. Corporate or institutional names
        end
    may sometimes be required and because such names will often fail the is_good_vanc_name() and other format compliance
        return dlclose .. "</div>"
    tests, are wrapped in doubled parentheses ((corporate name)) to suppress the format tests.
     
    Supports generational suffixes Jr, 2nd, 3rd, 4th–6th.
     
    This function sets the Vancouver error when a required comma is missing and when there is a space between an author's initials.
     
    ]]
     
    local function parse_vauthors_veditors (args, vparam, list_name)
    local names = {}; -- table of names assembled from |vauthors=, |author-maskn=, |author-linkn=
    local v_name_table = {};
    local v_link_table = {}; -- when name is wikilinked, targets go in this table
    local etal = false; -- return value set to true when we find some form of et al. vauthors parameter
    local last, first, link, mask, suffix;
    local corporate = false;
     
    vparam, etal = name_has_etal (vparam, etal, true); -- find and remove variations on et al. do not categorize (do it here because et al. might have a period)
    v_name_table = get_v_name_table (vparam, v_name_table, v_link_table); -- names are separated by commas
     
    for i, v_name in ipairs(v_name_table) do
    first = ''; -- set to empty string for concatenation and because it may have been set for previous author/editor
    local accept_name;
    v_name, accept_name = utilities.has_accept_as_written (v_name); -- remove accept-this-as-written markup when it wraps all of <v_name>
     
    if accept_name then
    last = v_name;
    corporate = true; -- flag used in list_people()
    elseif string.find(v_name, "%s") then
    if v_name:find('[;%.]') then -- look for commonly occurring punctuation characters;
    add_vanc_error (cfg.err_msg_supl.punctuation, i);
    end
    local lastfirstTable = {}
    lastfirstTable = mw.text.split(v_name, "%s+")
    first = table.remove(lastfirstTable); -- removes and returns value of last element in table which should be initials or generational suffix
     
    if not mw.ustring.match (first, '^%u+$') then -- mw.ustring here so that later we will catch non-Latin characters
    suffix = first; -- not initials so assume that whatever we got is a generational suffix
    first = table.remove(lastfirstTable); -- get what should be the initials from the table
    end
    last = table.concat(lastfirstTable, ' ') -- returns a string that is the concatenation of all other names that are not initials and generational suffix
    if not utilities.is_set (last) then
    first = ''; -- unset
    last = v_name; -- last empty because something wrong with first
    add_vanc_error (cfg.err_msg_supl.name, i);
    end
    if mw.ustring.match (last, '%a+%s+%u+%s+%a+') then
    add_vanc_error (cfg.err_msg_supl['missing comma'], i); -- matches last II last; the case when a comma is missing
    end
    if mw.ustring.match (v_name, ' %u %u$') then -- this test is in the wrong place TODO: move or replace with a more appropriate test
    add_vanc_error (cfg.err_msg_supl.initials, i); -- matches a space between two initials
    end
    else
    last = v_name; -- last name or single corporate name?  Doesn't support multiword corporate names? do we need this?
    end
    if utilities.is_set (first) then
    if not mw.ustring.match (first, "^%u?%u$") then -- first shall contain one or two upper-case letters, nothing else
    add_vanc_error (cfg.err_msg_supl.initials, i); -- too many initials; mixed case initials (which may be ok Romanization); hyphenated initials
    end
    is_good_vanc_name (last, first, suffix, i); -- check first and last before restoring the suffix which may have a non-Latin digit
    if utilities.is_set (suffix) then
    first = first .. ' ' .. suffix; -- if there was a suffix concatenate with the initials
    suffix = ''; -- unset so we don't add this suffix to all subsequent names
    end
    else
    if not corporate then
    is_good_vanc_name (last, '', nil, i);
    end
    end
     
    link = utilities.select_one ( args, cfg.aliases[list_name .. '-Link'], 'err_redundant_parameters', i ) or v_link_table[i];
    mask = utilities.select_one ( args, cfg.aliases[list_name .. '-Mask'], 'err_redundant_parameters', i );
    names[i] = {last = last, first = first, link = link, mask = mask, corporate = corporate}; -- add this assembled name to our names list
    end
    return names, etal; -- all done, return our list of names
    end
    end


    -- This is used by {{doi}} to create DOI links in the style used in citations.
     
    function z.doi(frame)
    --[[--------------------------< S E L E C T _ A U T H O R _ E D I T O R _ S O U R C E >------------------------
        local pframe = frame:getParent()
     
        local id = pframe.args.id or pframe.args[1] or ""
    Select one of |authors=, |authorn= / |lastn / firstn=, or |vauthors= as the source of the author name list or
        return doi(frame, id)
    select one of |editorn= / editor-lastn= / |editor-firstn= or |veditors= as the source of the editor name list.
     
    Only one of these appropriate three will be used.  The hierarchy is: |authorn= (and aliases) highest and |authors= lowest;
    |editorn= (and aliases) highest and |veditors= lowest (support for |editors= withdrawn)
     
    When looking for |authorn= / |editorn= parameters, test |xxxxor1= and |xxxxor2= (and all of their aliases); stops after the second
    test which mimicks the test used in extract_names() when looking for a hole in the author name list.  There may be a better
    way to do this, I just haven't discovered what that way is.
     
    Emits an error message when more than one xxxxor name source is provided.
     
    In this function, vxxxxors = vauthors or veditors; xxxxors = authors as appropriate.
     
    ]]
     
    local function select_author_editor_source (vxxxxors, xxxxors, args, list_name)
    local lastfirst = false;
    if utilities.select_one ( args, cfg.aliases[list_name .. '-Last'], 'none', 1 ) or -- do this twice in case we have a |first1= without a |last1=; this ...
    utilities.select_one ( args, cfg.aliases[list_name .. '-First'], 'none', 1 ) or -- ... also catches the case where |first= is used with |vauthors=
    utilities.select_one ( args, cfg.aliases[list_name .. '-Last'], 'none', 2 ) or
    utilities.select_one ( args, cfg.aliases[list_name .. '-First'], 'none', 2 ) then
    lastfirst = true;
    end
     
    if (utilities.is_set (vxxxxors) and true == lastfirst) or -- these are the three error conditions
    (utilities.is_set (vxxxxors) and utilities.is_set (xxxxors)) or
    (true == lastfirst and utilities.is_set (xxxxors)) then
    local err_name;
    if 'AuthorList' == list_name then -- figure out which name should be used in error message
    err_name = 'author';
    else
    err_name = 'editor';
    end
    table.insert( z.message_tail, { utilities.set_message ( 'err_redundant_parameters',
    {err_name .. '-name-list parameters'}, true ) } ); -- add error message
    end
     
    if true == lastfirst then return 1 end; -- return a number indicating which author name source to use
    if utilities.is_set (vxxxxors) then return 2 end;
    if utilities.is_set (xxxxors) then return 3 end;
    return 1; -- no authors so return 1; this allows missing author name test to run in case there is a first without last
    end
    end


    -- This is used by {{ISSN}} to create ISSN links in the style used in citations.
     
    function z.ISSN(frame)
    --[[--------------------------< I S _ V A L I D _ P A R A M E T E R _ V A L U E >------------------------------
        local pframe = frame:getParent()
     
        local Name = pframe.args[1] or ""
    This function is used to validate a parameter's assigned value for those parameters that have only a limited number
        return hideinprint(frame, "[[International Standard Serial Number|ISSN]]&nbsp;[http://www.worldcat.org/search?fq=x0:jrnl&q=n2:" .. Name .. " " .. Name .. "]")
    of allowable values (yes, y, true, live, dead, etc.).  When the parameter value has not been assigned a value (missing
    or empty in the source template) the function returns the value specified by ret_val. If the parameter value is one
    of the list of allowed values returns the translated value; else, emits an error message and returns the value
    specified by ret_val.
     
    ]]
     
    local function is_valid_parameter_value (value, name, possible, ret_val)
    if not utilities.is_set (value) then
    return ret_val; -- an empty parameter is ok
    elseif utilities.in_array (value, possible) then
    return cfg.keywords_xlate[value]; -- return translation of parameter keyword
    else
    table.insert( z.message_tail, { utilities.set_message ( 'err_invalid_param_val', {name, value}, true ) } ); -- not an allowed value so add error message
    return ret_val;
    end
    end
    end


    -- This is used by templates such as {{SfnRef}} to create the (encoded) anchor name for a Harvard cross-reference hyperlink.
     
    function z.SFNID(frame)
    --[[--------------------------< T E R M I N A T E _ N A M E _ L I S T >----------------------------------------
        local pframe = frame:getParent()
     
        return anchorid(pframe.args)
    This function terminates a name list (author, contributor, editor) with a separator character (sepc) and a space
    when the last character is not a sepc character or when the last three characters are not sepc followed by two
    closing square brackets (close of a wikilink).  When either of these is true, the name_list is terminated with a
    single space character.
     
    ]]
     
    local function terminate_name_list (name_list, sepc)
    if (string.sub (name_list, -3, -1) == sepc .. '. ') then -- if already properly terminated
    return name_list; -- just return the name list
    elseif (string.sub (name_list, -1, -1) == sepc) or (string.sub (name_list, -3, -1) == sepc .. ']]') then -- if last name in list ends with sepc char
    return name_list .. " "; -- don't add another
    else
    return name_list .. sepc .. ' '; -- otherwise terminate the name list
    end
    end
    end


    -- This is used by templates such as {{Harvard citation}} to create the Harvard cross-reference text.
     
    function z.Harvard(frame)
    --[[-------------------------< F O R M A T _ V O L U M E _ I S S U E >----------------------------------------
        local pframe = frame:getParent()
     
        return crossref(frame, pframe.args)
    returns the concatenation of the formatted volume and issue parameters as a single string; or formatted volume
    or formatted issue, or an empty string if neither are set.
     
    ]]
    local function format_volume_issue (volume, issue, cite_class, origin, sepc, lower)
    if not utilities.is_set (volume) and not utilities.is_set (issue) then
    return '';
    end
    if 'magazine' == cite_class or (utilities.in_array (cite_class, {'citation', 'map'}) and 'magazine' == origin) then
    if utilities.is_set (volume) and utilities.is_set (issue) then
    return wrap_msg ('vol-no', {sepc, hyphen_to_dash (volume), issue}, lower);
    elseif utilities.is_set (volume) then
    return wrap_msg ('vol', {sepc, hyphen_to_dash (volume)}, lower);
    else
    return wrap_msg ('issue', {sepc, issue}, lower);
    end
    end
     
    if 'podcast' == cite_class and utilities.is_set (issue) then
    return wrap_msg ('issue', {sepc, issue}, lower);
    end
     
    local vol = ''; -- here for all cites except magazine
    if utilities.is_set (volume) then
    if volume:match ('^[MDCLXVI]+$') or volume:match ('^%d+$') then -- volume value is all digits or all uppercase Roman numerals
    vol = utilities.substitute (cfg.presentation['vol-bold'], {sepc, volume}); -- render in bold face
    elseif (4 < mw.ustring.len(volume)) then -- not all digits or Roman numerals and longer than 4 characters
    vol = utilities.substitute (cfg.messages['j-vol'], {sepc, hyphen_to_dash (volume)}); -- not bold
    utilities.add_prop_cat ('long_vol');
    else -- four or less characters
    vol = utilities.substitute (cfg.presentation['vol-bold'], {sepc, hyphen_to_dash (volume)}); -- bold
    end
    end
    if utilities.is_set (issue) then
    return vol .. utilities.substitute (cfg.messages['j-issue'], issue);
    end
    return vol;
    end
    end


    -- This is used by templates such as {{cite book}} to create the actual citation text.
     
    function z.citation(frame)
    --[[-------------------------< F O R M A T _ P A G E S _ S H E E T S >-----------------------------------------
        local pframe = frame:getParent()
     
       
    adds static text to one of |page(s)= or |sheet(s)= values and returns it with all of the others set to empty strings.
        local args = {};
    The return order is:
        for k, v in pairs( pframe.args ) do
    page, pages, sheet, sheets
            args[k] = v;
     
        end   
    Singular has priority over plural when both are provided.
        return citation0(frame, args)
     
    ]]
     
    local function format_pages_sheets (page, pages, sheet, sheets, cite_class, origin, sepc, nopp, lower)
    if 'map' == cite_class then -- only cite map supports sheet(s) as in-source locators
    if utilities.is_set (sheet) then
    if 'journal' == origin then
    return '', '', wrap_msg ('j-sheet', sheet, lower), '';
    else
    return '', '', wrap_msg ('sheet', {sepc, sheet}, lower), '';
    end
    elseif utilities.is_set (sheets) then
    if 'journal' == origin then
    return '', '', '', wrap_msg ('j-sheets', sheets, lower);
    else
    return '', '', '', wrap_msg ('sheets', {sepc, sheets}, lower);
    end
    end
    end
     
    local is_journal = 'journal' == cite_class or (utilities.in_array (cite_class, {'citation', 'map', 'interview'}) and 'journal' == origin);
    if utilities.is_set (page) then
    if is_journal then
    return utilities.substitute (cfg.messages['j-page(s)'], page), '', '', '';
    elseif not nopp then
    return utilities.substitute (cfg.messages['p-prefix'], {sepc, page}), '', '', '';
    else
    return utilities.substitute (cfg.messages['nopp'], {sepc, page}), '', '', '';
    end
    elseif utilities.is_set (pages) then
    if is_journal then
    return utilities.substitute (cfg.messages['j-page(s)'], pages), '', '', '';
    elseif tonumber(pages) ~= nil and not nopp then -- if pages is only digits, assume a single page number
    return '', utilities.substitute (cfg.messages['p-prefix'], {sepc, pages}), '', '';
    elseif not nopp then
    return '', utilities.substitute (cfg.messages['pp-prefix'], {sepc, pages}), '', '';
    else
    return '', utilities.substitute (cfg.messages['nopp'], {sepc, pages}), '', '';
    end
    end
    return '', '', '', ''; -- return empty strings
    end
    end


    -- This is used by templates such as {{sfn}} to create the entire cross-reference.
     
    function z.sfn(frame)
    --[[--------------------------< I N S O U R C E _ L O C _ G E T >----------------------------------------------
        local pframe = frame:getParent()
     
        local content = crossref(frame, pframe.args)
    returns one of the in-source locators: page, pages, or at.
        local args = { name = refid(pframe.args) }
     
        return z.mw.text.tag({name = "ref", contents = content, params = args}, frame)
    If any of these are interwiki links to Wikisource, returns the label portion of the interwiki-link as plain text
    for use in COinS.  This COinS thing is done because here we convert an interwiki-link to an external link and
    add an icon span around that; get_coins_pages() doesn't know about the span.  TODO: should it? 
     
    TODO: add support for sheet and sheets?; streamline;
     
    TODO: make it so that this function returns only one of the three as the single in-source (the return value assigned
    to a new name)?
     
    ]]
     
    local function insource_loc_get (page, page_orig, pages, pages_orig, at)
    local ws_url, ws_label, coins_pages, L; -- for Wikisource interwiki-links; TODO: this corrupts page metadata (span remains in place after cleanup; fix there?)
     
    if utilities.is_set (page) then
    if utilities.is_set (pages) or utilities.is_set (at) then
    pages = ''; -- unset the others
    at = '';
    end
    extra_text_in_page_check (page, page_orig); -- emit error message when |page= value begins with what looks like p., pp., etc.
     
    ws_url, ws_label, L = wikisource_url_make (page); -- make ws URL from |page= interwiki link; link portion L becomes tooltip label
    if ws_url then
    page = external_link (ws_url, ws_label .. '&nbsp;', 'ws link in page'); -- space char after label to move icon away from in-source text; TODO: a better way to do this?
    page = utilities.substitute (cfg.presentation['interwiki-icon'], {cfg.presentation['class-wikisource'], L, page});
    coins_pages = ws_label;
    end
    elseif utilities.is_set (pages) then
    if utilities.is_set (at) then
    at = ''; -- unset
    end
    extra_text_in_page_check (pages, pages_orig); -- emit error message when |page= value begins with what looks like p., pp., etc.
     
    ws_url, ws_label, L = wikisource_url_make (pages); -- make ws URL from |pages= interwiki link; link portion L becomes tooltip label
    if ws_url then
    pages = external_link (ws_url, ws_label .. '&nbsp;', 'ws link in pages'); -- space char after label to move icon away from in-source text; TODO: a better way to do this?
    pages = utilities.substitute (cfg.presentation['interwiki-icon'], {cfg.presentation['class-wikisource'], L, pages});
    coins_pages = ws_label;
    end
    elseif utilities.is_set (at) then
    ws_url, ws_label, L = wikisource_url_make (at); -- make ws URL from |at= interwiki link; link portion L becomes tooltip label
    if ws_url then
    at = external_link (ws_url, ws_label .. '&nbsp;', 'ws link in at'); -- space char after label to move icon away from in-source text; TODO: a better way to do this?
    at = utilities.substitute (cfg.presentation['interwiki-icon'], {cfg.presentation['class-wikisource'], L, at});
    coins_pages = ws_label;
    end
    end
    return page, pages, at, coins_pages;
    end
    end


    -- This is used by template {{r}}.
    --[[--------------------------< I S _ U N I Q U E _ A R C H I V E _ U R L >------------------------------------
    function z.r(frame)
     
        local pframe = frame:getParent()
    add error message when |archive-url= value is same as |url= or chapter-url= (or alias...) value
        local config = frame.args -- the arguments passed BY the template, in the wikitext of the template itself
     
        local args = pframe.args -- the arguments passed TO the template, in the wikitext that instantiates the template
    ]]
        args.page1 = args.page1 or args.page
     
        local text = ""
    local function is_unique_archive_url (archive, url, c_url, source, date)
        -- This would be shorter using ipairs(), but that doesn't work on an arguments table supplied to a template.
    if utilities.is_set (archive) then
        local index = 1
    if archive == url or archive == c_url then
        while args[index] ~= nil do
    table.insert (z.message_tail, {utilities.set_message ('err_bad_url', {utilities.wrap_style ('parameter', source)}, true)}); -- add error message
            local arg = args[index]
    return '', ''; -- unset |archive-url= and |archive-date= because same as |url= or |chapter-url=
            local t = r0(frame, arg, args.group, args["page" .. index])
    end
            text = text .. t
    end
            index = index + 1
     
        end
    return archive, date;
        return text
    end
    end


    -- This is used by template {{ref label}}.
     
    function z.reflabel(frame)
    --[=[-------------------------< A R C H I V E _ U R L _ C H E C K >--------------------------------------------
        local pframe = frame:getParent()
     
        local config = frame.args -- the arguments passed BY the template, in the wikitext of the template itself
    Check archive.org URLs to make sure they at least look like they are pointing at valid archives and not to the
        local args = pframe.args -- the arguments passed TO the template, in the wikitext that instantiates the template
    save snapshot URL or to calendar pages.  When the archive URL is 'https://web.archive.org/save/' (or http://...)
        local P1 = args[1] or ""
    archive.org saves a snapshot of the target page in the URL.  That is something that Wikipedia should not allow
        local P2 = args[2] or ""
    unwitting readers to do.
        local P3 = args[3] or ""
     
        local id = nil
    When the archive.org URL does not have a complete timestamp, archive.org chooses a snapshot according to its own
        local contents = "[[#endnote_" .. P1 .. P3 .. "|&#91;" .. P2 .. "&#93;]]"
    algorithm or provides a calendar 'search' result.  [[WP:ELNO]] discourages links to search results.
        local params = {}
     
        params.class="reference"
    This function looks at the value assigned to |archive-url= and returns empty strings for |archive-url= and
        if ( args.noid == nil or args.noid == "" ) then params.id = "ref_" .. P1 .. P3 end
    |archive-date= and an error message when:
        return z.mw.text.tag({name="sup",contents=contents,params=params})
    |archive-url= holds an archive.org save command URL
    |archive-url= is an archive.org URL that does not have a complete timestamp (YYYYMMDDhhmmss 14 digits) in the
    correct place
    otherwise returns |archive-url= and |archive-date=
     
    There are two mostly compatible archive.org URLs:
    //web.archive.org/<timestamp>... -- the old form
    //web.archive.org/web/<timestamp>... -- the new form
     
    The old form does not support or map to the new form when it contains a display flag.  There are four identified flags
    ('id_', 'js_', 'cs_', 'im_') but since archive.org ignores others following the same form (two letters and an underscore)
    we don't check for these specific flags but we do check the form.
     
    This function supports a preview mode. When the article is rendered in preview mode, this function may return a modified
    archive URL:
    for save command errors, return undated wildcard (/*/)
    for timestamp errors when the timestamp has a wildcard, return the URL unmodified
    for timestamp errors when the timestamp does not have a wildcard, return with timestamp limited to six digits plus wildcard (/yyyymm*/)
     
    ]=]
     
    local function archive_url_check (url, date)
    local err_msg = ''; -- start with the error message empty
    local path, timestamp, flag; -- portions of the archive.org URL
    if (not url:match('//web%.archive%.org/')) and (not url:match('//liveweb%.archive%.org/')) then -- also deprecated liveweb Wayback machine URL
    return url, date; -- not an archive.org archive, return ArchiveURL and ArchiveDate
    end
     
    if url:match('//web%.archive%.org/save/') then -- if a save command URL, we don't want to allow saving of the target page
    err_msg = cfg.err_msg_supl.save;
    url = url:gsub ('(//web%.archive%.org)/save/', '%1/*/', 1); -- for preview mode: modify ArchiveURL
    elseif url:match('//liveweb%.archive%.org/') then
    err_msg = cfg.err_msg_supl.liveweb;
    else
    path, timestamp, flag = url:match('//web%.archive%.org/([^%d]*)(%d+)([^/]*)/'); -- split out some of the URL parts for evaluation
    if not utilities.is_set (timestamp) or 14 ~= timestamp:len() then -- path and flag optional, must have 14-digit timestamp here
    err_msg = cfg.err_msg_supl.timestamp;
    if '*' ~= flag then
    url=url:gsub ('(//web%.archive%.org/[^%d]*%d?%d?%d?%d?%d?%d?)[^/]*', '%1*', 1) -- for preview, modify ts to be yearmo* max (0-6 digits plus splat)
    end
    elseif utilities.is_set (path) and 'web/' ~= path then -- older archive URLs do not have the extra 'web/' path element
    err_msg = cfg.err_msg_supl.path;
    elseif utilities.is_set (flag) and not utilities.is_set (path) then -- flag not allowed with the old form URL (without the 'web/' path element)
    err_msg = cfg.err_msg_supl.flag;
    elseif utilities.is_set (flag) and not flag:match ('%a%a_') then -- flag if present must be two alpha characters and underscore (requires 'web/' path element)
    err_msg = cfg.err_msg_supl.flag;
    else
    return url, date; -- return ArchiveURL and ArchiveDate
    end
    end
    -- if here, something not right so
    table.insert( z.message_tail, { utilities.set_message ( 'err_archive_url', {err_msg}, true ) } ); -- add error message and
    if utilities.is_set (Frame:preprocess('{{REVISIONID}}')) then
    return '', ''; -- return empty strings for ArchiveURL and ArchiveDate
    else
    return url, date; -- preview mode so return ArchiveURL and ArchiveDate
    end
    end
    end


    -- This is used by template {{note label}}.
     
    function z.notelabel(frame)
    --[[--------------------------< P L A C E _ C H E C K >--------------------------------------------------------
        local pframe = frame:getParent()
     
        local config = frame.args -- the arguments passed BY the template, in the wikitext of the template itself
    check |place=, |publication-place=, |location= to see if these params include digits. This function added because
        local args = pframe.args -- the arguments passed TO the template, in the wikitext that instantiates the template
    many editors misuse location to specify the in-source location (|page(s)= and |at= are supposed to do that)
        local id = args[1] or ""
     
        local arrow = args[3] or ""
    returns the original parameter value without modification; added maint cat when parameter value contains digits
        local postscript = args[4] or ""
     
        local contents
    ]]
        if arrow ~= "" then
     
            local sup_arrow = z.mw.text.tag({name="sup",contents=arrow,params={}})
    local function place_check (param_val)
            contents = "[[#ref_" .. id .. arrow .. "|<b>" .. sup_arrow .. "</b>]]" .. postscript
    if not utilities.is_set (param_val) then -- parameter empty or omitted
            if "none" == arrow then arrow = "^" end -- Change this AFTER using it in the ID parameter and the contents.
    return param_val; -- return that empty state
        else
    end
            contents = (args[2] or "") .. postscript
        end
    if mw.ustring.find (param_val, '%d') then -- not empty, are there digits in the parameter value
        local params = { class="citation wikicite" }
    utilities.set_message ('maint_location'); -- yep, add maint cat
        if id ~= "" and ( args.noid == nil or args.noid == "" ) then  
    end
            params.id = z.mw.url.encodeAnchor("endnote_" .. id .. arrow)
        end
    return param_val; -- and done
        return z.mw.text.tag({name="span",contents=contents,params=params})
    end
    end


    -- This is used by templates {{reflist}} and {{notelist}}.
     
    function z.reflist(frame)
    --[[--------------------------< I S _ G E N E R I C _ T I T L E >----------------------------------------------
        local pframe = frame:getParent()
     
        local config = frame.args -- the arguments passed BY the template, in the wikitext of the template itself
    compares |title= value against list of known generic title patterns.  Returns true when pattern matches; nil else
        local args = pframe.args -- the arguments passed TO the template, in the wikitext that instantiates the template
     
        return reflist0(frame, config, args)
    the k/v pairs in 'generic_titles' each contain two tables, one for English and one for another 'local' language
    Each of those tables contain another table that holds the string or pattern (whole title or title fragment) in
    index [1].  index [2] is a Boolean that tells string.find() or mw.ustring.find() to do plain-text search (true)
    or a pattern search (false).  The intent of all this complexity is to make these searches as fast as possible so
    that we don't run out of processing time on very large articles.
     
    ]]
     
    local function is_generic_title (title)
    title = mw.ustring.lower(title); -- switch title to lower case
    for _, generic_title in ipairs (cfg.special_case_translation['generic_titles']) do -- spin through the list of known generic title fragments
    if title:find (generic_title['en'][1], 1, generic_title['en'][2]) then
    return true; -- found English generic title so done
    elseif generic_title['local'] then -- to keep work load down, generic_title['local'] should be nil except when there is a local version of the generic title
    if mw.ustring.find (title, generic_title['local'][1], 1, generic_title['local'][2]) then -- mw.ustring() because might not be Latin script
    return true; -- found local generic title so done
    end
    end
    end
    end
    end


    -- This is used by template {{refbegin}}.
     
    function z.refbegin(frame)
    --[[--------------------------< I S _ A R C H I V E D _ C O P Y >----------------------------------------------
        local pframe = frame:getParent()
     
        local config = frame.args -- the arguments passed BY the template, in the wikitext of the template itself
    compares |title= to 'Archived copy' (placeholder added by bots that can't find proper title); if matches, return true; nil else
        local args = pframe.args -- the arguments passed TO the template, in the wikitext that instantiates the template
     
        return refbegin0(frame, config, args)
    ]]
     
    local function is_archived_copy (title)
    title = mw.ustring.lower(title); -- switch title to lower case
    if title:find (cfg.special_case_translation.archived_copy.en) then -- if title is 'Archived copy'
    return true;
    elseif cfg.special_case_translation.archived_copy['local'] then
    if mw.ustring.find (title, cfg.special_case_translation.archived_copy['local']) then -- mw.ustring() because might not be Latin script
    return true;
    end
    end
    end
    end


    -- This is used by template {{refend}}.
     
    function z.refend(frame)
    --[[--------------------------< C I T A T I O N 0 >------------------------------------------------------------
        local pframe = frame:getParent()
     
        local config = frame.args -- the arguments passed BY the template, in the wikitext of the template itself
    This is the main function doing the majority of the citation formatting.
        local args = pframe.args -- the arguments passed TO the template, in the wikitext that instantiates the template
     
        return refend0(frame, config, args)
    ]]
     
    local function citation0( config, args )
    --[[
    Load Input Parameters
    The argument_wrapper facilitates the mapping of multiple aliases to single internal variable.
    ]]
    local A = argument_wrapper ( args );
    local i
     
    -- Pick out the relevant fields from the arguments.  Different citation templates
    -- define different field names for the same underlying things.
     
    local author_etal;
    local a = {}; -- authors list from |lastn= / |firstn= pairs or |vauthors=
    local Authors;
    local NameListStyle = is_valid_parameter_value (A['NameListStyle'], A:ORIGIN('NameListStyle'), cfg.keywords_lists['name-list-style'], '');
    local Collaboration = A['Collaboration'];
     
    do -- to limit scope of selected
    local selected = select_author_editor_source (A['Vauthors'], A['Authors'], args, 'AuthorList');
    if 1 == selected then
    a, author_etal = extract_names (args, 'AuthorList'); -- fetch author list from |authorn= / |lastn= / |firstn=, |author-linkn=, and |author-maskn=
    elseif 2 == selected then
    NameListStyle = 'vanc'; -- override whatever |name-list-style= might be
    a, author_etal = parse_vauthors_veditors (args, args.vauthors, 'AuthorList'); -- fetch author list from |vauthors=, |author-linkn=, and |author-maskn=
    elseif 3 == selected then
    Authors = A['Authors']; -- use content of |authors=
    if 'authors' == A:ORIGIN('Authors') then -- but add a maint cat if the parameter is |authors=
    utilities.set_message ('maint_authors'); -- because use of this parameter is discouraged; what to do about the aliases is a TODO:
    end
    end
    if utilities.is_set (Collaboration) then
    author_etal = true; -- so that |display-authors=etal not required
    end
    end
     
    local editor_etal;
    local e = {}; -- editors list from |editor-lastn= / |editor-firstn= pairs or |veditors=
     
    do -- to limit scope of selected
    local selected = select_author_editor_source (A['Veditors'], nil, args, 'EditorList'); -- support for |editors= withdrawn
    if 1 == selected then
    e, editor_etal = extract_names (args, 'EditorList'); -- fetch editor list from |editorn= / |editor-lastn= / |editor-firstn=, |editor-linkn=, and |editor-maskn=
    elseif 2 == selected then
    NameListStyle = 'vanc'; -- override whatever |name-list-style= might be
    e, editor_etal = parse_vauthors_veditors (args, args.veditors, 'EditorList'); -- fetch editor list from |veditors=, |editor-linkn=, and |editor-maskn=
    end
    end
    local Chapter = A['Chapter']; -- done here so that we have access to |contribution= from |chapter= aliases
    local Chapter_origin = A:ORIGIN ('Chapter');
    local Contribution; -- because contribution is required for contributor(s)
    if 'contribution' == Chapter_origin then
    Contribution = Chapter; -- get the name of the contribution
    end
    local c = {}; -- contributors list from |contributor-lastn= / contributor-firstn= pairs
    if utilities.in_array (config.CitationClass, {"book", "citation"}) and not utilities.is_set (A['Periodical']) then -- |contributor= and |contribution= only supported in book cites
    c = extract_names (args, 'ContributorList'); -- fetch contributor list from |contributorn= / |contributor-lastn=, -firstn=, -linkn=, -maskn=
    if 0 < #c then
    if not utilities.is_set (Contribution) then -- |contributor= requires |contribution=
    table.insert( z.message_tail, { utilities.set_message ( 'err_contributor_missing_required_param', 'contribution')}); -- add missing contribution error message
    c = {}; -- blank the contributors' table; it is used as a flag later
    end
    if 0 == #a then -- |contributor= requires |author=
    table.insert( z.message_tail, { utilities.set_message ( 'err_contributor_missing_required_param', 'author')}); -- add missing author error message
    c = {}; -- blank the contributors' table; it is used as a flag later
    end
    end
    else -- if not a book cite
    if utilities.select_one (args, cfg.aliases['ContributorList-Last'], 'err_redundant_parameters', 1 ) then -- are there contributor name list parameters?
    table.insert( z.message_tail, { utilities.set_message ( 'err_contributor_ignored')}); -- add contributor ignored error message
    end
    Contribution = nil; -- unset
    end
     
    local Title = A['Title'];
    local TitleLink = A['TitleLink'];
     
    local auto_select = ''; -- default is auto
    local accept_link;
    TitleLink, accept_link = utilities.has_accept_as_written(TitleLink, true); -- test for accept-this-as-written markup
    if (not accept_link) and utilities.in_array (TitleLink, {'none', 'pmc', 'doi'}) then -- check for special keywords
    auto_select = TitleLink; -- remember selection for later
    TitleLink = ''; -- treat as if |title-link= would have been empty
    end
     
    TitleLink = link_title_ok (TitleLink, A:ORIGIN ('TitleLink'), Title, 'title'); -- check for wiki-markup in |title-link= or wiki-markup in |title= when |title-link= is set
     
    local Section = ''; -- {{cite map}} only; preset to empty string for concatenation if not used
    if 'map' == config.CitationClass and 'section' == Chapter_origin then
    Section = A['Chapter']; -- get |section= from |chapter= alias list; |chapter= and the other aliases not supported in {{cite map}}
    Chapter = ''; -- unset for now; will be reset later from |map= if present
    end
     
    local Periodical = A['Periodical'];
    local Periodical_origin = '';
    if utilities.is_set (Periodical) then
    Periodical_origin = A:ORIGIN('Periodical'); -- get the name of the periodical parameter
    local i;
    Periodical, i = utilities.strip_apostrophe_markup (Periodical); -- strip apostrophe markup so that metadata isn't contaminated
    if i then -- non-zero when markup was stripped so emit an error message
    table.insert( z.message_tail, {utilities.set_message ('err_apostrophe_markup', {Periodical_origin}, true)});
    end
    end
     
    if 'mailinglist' == config.CitationClass then -- special case for {{cite mailing list}}
    if utilities.is_set (Periodical) and utilities.is_set (A ['MailingList']) then -- both set emit an error
    table.insert( z.message_tail, {utilities.set_message ('err_redundant_parameters', {utilities.wrap_style ('parameter', Periodical_origin) .. ' and ' .. utilities.wrap_style ('parameter', 'mailinglist')}, true )});
    end
     
    Periodical = A ['MailingList']; -- error or no, set Periodical to |mailinglist= value because this template is {{cite mailing list}}
    Periodical_origin = A:ORIGIN('MailingList');
    end
     
    local ScriptPeriodical = A['ScriptPeriodical'];
     
    -- web and news not tested for now because of
    -- Wikipedia:Administrators%27_noticeboard#Is_there_a_semi-automated_tool_that_could_fix_these_annoying_"Cite_Web"_errors?
    if not (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical)) then -- 'periodical' templates require periodical parameter
    -- local p = {['journal'] = 'journal', ['magazine'] = 'magazine', ['news'] = 'newspaper', ['web'] = 'website'}; -- for error message
    local p = {['journal'] = 'journal', ['magazine'] = 'magazine'}; -- for error message
    if p[config.CitationClass]  then
    table.insert( z.message_tail, {utilities.set_message ('err_missing_periodical', {config.CitationClass, p[config.CitationClass]}, true)});
    end
    end
    local Volume;
    local ScriptPeriodical_origin = A:ORIGIN('ScriptPeriodical');
    if 'citation' == config.CitationClass then
    if utilities.is_set (Periodical) then
    if not utilities.in_array (Periodical_origin, {'website', 'mailinglist'}) then -- {{citation}} does not render volume for these 'periodicals'
    Volume = A['Volume']; -- but does for all other 'periodicals'
    end
    elseif utilities.is_set (ScriptPeriodical) then
    if 'script-website' ~= ScriptPeriodical_origin then -- {{citation}} does not render volume for |script-website=
    Volume = A['Volume']; -- but does for all other 'periodicals'
    end
    else
    Volume = A['Volume']; -- and does for non-'periodical' cites
    end
    elseif utilities.in_array (config.CitationClass, cfg.templates_using_volume) then -- render |volume= for cs1 according to the configuration settings
    Volume = A['Volume'];
    end
    extra_text_in_vol_iss_check (Volume, A:ORIGIN ('Volume'), 'v');
     
    local Issue;
    if 'citation' == config.CitationClass then
    if utilities.is_set (Periodical) and utilities.in_array (Periodical_origin, {'journal', 'magazine', 'newspaper', 'periodical', 'work'}) or -- {{citation}} renders issue for these 'periodicals'
    utilities.is_set (ScriptPeriodical) and utilities.in_array (ScriptPeriodical_origin, {'script-journal', 'script-magazine', 'script-newspaper', 'script-periodical', 'script-work'}) then -- and these 'script-periodicals'
    Issue = hyphen_to_dash (A['Issue']);
    end
    elseif utilities.in_array (config.CitationClass, cfg.templates_using_issue) then -- conference & map books do not support issue; {{citation}} listed here because included in settings table
    if not (utilities.in_array (config.CitationClass, {'conference', 'map', 'citation'}) and not (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical))) then
    Issue = hyphen_to_dash (A['Issue']);
    end
    end
    extra_text_in_vol_iss_check (Issue, A:ORIGIN ('Issue'), 'i');
     
    local Page;
    local Pages;
    local At;
    if not utilities.in_array (config.CitationClass, cfg.templates_not_using_page) then
    Page = A['Page'];
    Pages = hyphen_to_dash (A['Pages']);
    At = A['At'];
    end
     
    local Edition = A['Edition'];
    local PublicationPlace = place_check (A['PublicationPlace'], A:ORIGIN('PublicationPlace'));
    local Place = place_check (A['Place'], A:ORIGIN('Place'));
    local PublisherName = A['PublisherName'];
    local PublisherName_origin = A:ORIGIN('PublisherName');
    if utilities.is_set (PublisherName) then
    local i = 0;
    PublisherName, i = utilities.strip_apostrophe_markup (PublisherName); -- strip apostrophe markup so that metadata isn't contaminated; publisher is never italicized
    if i then -- non-zero when markup was stripped so emit an error message
    table.insert( z.message_tail, {utilities.set_message ('err_apostrophe_markup', {PublisherName_origin}, true)});
    end
    end
     
    local Newsgroup = A['Newsgroup']; -- TODO: strip apostrophe markup?
    local Newsgroup_origin = A:ORIGIN('Newsgroup');
     
    if 'newsgroup' == config.CitationClass then
    if utilities.is_set (PublisherName) then -- general use parameter |publisher= not allowed in cite newsgroup
    local error_text, error_state = utilities.set_message ('err_parameter_ignored', {PublisherName_origin}, true);
    if utilities.is_set (error_text) then
    table.insert( z.message_tail, {error_text, error_state} );
    end
    end
     
    PublisherName = nil; -- ensure that this parameter is unset for the time being; will be used again after COinS
    end
     
    local URL = A['URL']
    local UrlAccess = is_valid_parameter_value (A['UrlAccess'], A:ORIGIN('UrlAccess'), cfg.keywords_lists['url-access'], nil);
    if not utilities.is_set (URL) and utilities.is_set (UrlAccess) then
    UrlAccess = nil;
    table.insert( z.message_tail, { utilities.set_message ( 'err_param_access_requires_param', {'url'}, true ) } );
    end
    local ChapterURL = A['ChapterURL'];
    local ChapterUrlAccess = is_valid_parameter_value (A['ChapterUrlAccess'], A:ORIGIN('ChapterUrlAccess'), cfg.keywords_lists['url-access'], nil);
    if not utilities.is_set (ChapterURL) and utilities.is_set (ChapterUrlAccess) then
    ChapterUrlAccess = nil;
    table.insert( z.message_tail, { utilities.set_message ( 'err_param_access_requires_param', {A:ORIGIN('ChapterUrlAccess'):gsub ('%-access', '')}, true ) } );
    end
     
    local MapUrlAccess = is_valid_parameter_value (A['MapUrlAccess'], A:ORIGIN('MapUrlAccess'), cfg.keywords_lists['url-access'], nil);
    if not utilities.is_set (A['MapURL']) and utilities.is_set (MapUrlAccess) then
    MapUrlAccess = nil;
    table.insert( z.message_tail, { utilities.set_message ( 'err_param_access_requires_param', {'map-url'}, true ) } );
    end
     
    local this_page = mw.title.getCurrentTitle(); -- also used for COinS and for language
    local no_tracking_cats = is_valid_parameter_value (A['NoTracking'], A:ORIGIN('NoTracking'), cfg.keywords_lists['yes_true_y'], nil);
     
    -- check this page to see if it is in one of the namespaces that cs1 is not supposed to add to the error categories
    if not utilities.is_set (no_tracking_cats) then -- ignore if we are already not going to categorize this page
    if utilities.in_array (this_page.nsText, cfg.uncategorized_namespaces) then
    no_tracking_cats = "true"; -- set no_tracking_cats
    end
    for _, v in ipairs (cfg.uncategorized_subpages) do -- cycle through page name patterns
    if this_page.text:match (v) then -- test page name against each pattern
    no_tracking_cats = "true"; -- set no_tracking_cats
    break; -- bail out if one is found
    end
    end
    end
    -- check for extra |page=, |pages= or |at= parameters. (also sheet and sheets while we're at it)
    utilities.select_one (args, {'page', 'p', 'pp', 'pages', 'at', 'sheet', 'sheets'}, 'err_redundant_parameters'); -- this is a dummy call simply to get the error message and category
     
    local coins_pages;
    Page, Pages, At, coins_pages = insource_loc_get (Page, A:ORIGIN('Page'), Pages, A:ORIGIN('Pages'), At);
     
    local NoPP = is_valid_parameter_value (A['NoPP'], A:ORIGIN('NoPP'), cfg.keywords_lists['yes_true_y'], nil);
     
    if utilities.is_set (PublicationPlace) and utilities.is_set (Place) then -- both |publication-place= and |place= (|location=) allowed if different
    utilities.add_prop_cat ('location test'); -- add property cat to evaluate how often PublicationPlace and Place are used together
    if PublicationPlace == Place then
    Place = ''; -- unset; don't need both if they are the same
    end
    elseif not utilities.is_set (PublicationPlace) and utilities.is_set (Place) then -- when only |place= (|location=) is set ...
    PublicationPlace = Place; -- promote |place= (|location=) to |publication-place
    end
     
    if PublicationPlace == Place then Place = ''; end -- don't need both if they are the same
    local URL_origin = A:ORIGIN('URL'); -- get name of parameter that holds URL
    local ChapterURL_origin = A:ORIGIN('ChapterURL'); -- get name of parameter that holds ChapterURL
    local ScriptChapter = A['ScriptChapter'];
    local ScriptChapter_origin = A:ORIGIN ('ScriptChapter');
    local Format = A['Format'];
    local ChapterFormat = A['ChapterFormat'];
    local TransChapter = A['TransChapter'];
    local TransChapter_origin = A:ORIGIN ('TransChapter');
    local TransTitle = A['TransTitle'];
    local ScriptTitle = A['ScriptTitle'];
    --[[
    Parameter remapping for cite encyclopedia:
    When the citation has these parameters:
    |encyclopedia= and |title= then map |title= to |article= and |encyclopedia= to |title=
    |encyclopedia= and |article= then map |encyclopedia= to |title=
     
    |trans-title= maps to |trans-chapter= when |title= is re-mapped
    |url= maps to |chapter-url= when |title= is remapped
    All other combinations of |encyclopedia=, |title=, and |article= are not modified
    ]]
     
    local Encyclopedia = A['Encyclopedia']; -- used as a flag by this module and by ~/COinS
     
    if utilities.is_set (Encyclopedia) then -- emit error message when Encyclopedia set but template is other than {{cite encyclopedia}} or {{citation}}
    if 'encyclopaedia' ~= config.CitationClass and 'citation' ~= config.CitationClass then
    table.insert (z.message_tail, {utilities.set_message ('err_parameter_ignored', {A:ORIGIN ('Encyclopedia')}, true)});
    Encyclopedia = nil; -- unset because not supported by this template
    end
    end
     
    if ('encyclopaedia' == config.CitationClass) or ('citation' == config.CitationClass and utilities.is_set (Encyclopedia)) then
    if utilities.is_set (Periodical) and utilities.is_set (Encyclopedia) then -- when both set emit an error
    table.insert (z.message_tail, {utilities.set_message ('err_redundant_parameters', {utilities.wrap_style ('parameter', A:ORIGIN ('Encyclopedia')) .. ' and ' .. utilities.wrap_style ('parameter', Periodical_origin)}, true )});
    end
     
    if utilities.is_set (Encyclopedia) then
    Periodical = Encyclopedia; -- error or no, set Periodical to Encyclopedia; allow periodical without encyclopedia
    Periodical_origin = A:ORIGIN ('Encyclopedia');
    end
     
    if utilities.is_set (Periodical) then -- Periodical is set when |encyclopedia= is set
    if utilities.is_set (Title) or utilities.is_set (ScriptTitle) then
    if not utilities.is_set (Chapter) then
    Chapter = Title; -- |encyclopedia= and |title= are set so map |title= to |article= and |encyclopedia= to |title=
    ScriptChapter = ScriptTitle;
    ScriptChapter_origin = A:ORIGIN('ScriptTitle')
    TransChapter = TransTitle;
    ChapterURL = URL;
    ChapterURL_origin = URL_origin;
     
    ChapterUrlAccess = UrlAccess;
     
    if not utilities.is_set (ChapterURL) and utilities.is_set (TitleLink) then
    Chapter = utilities.make_wikilink (TitleLink, Chapter);
    end
    Title = Periodical;
    ChapterFormat = Format;
    Periodical = ''; -- redundant so unset
    TransTitle = '';
    URL = '';
    Format = '';
    TitleLink = '';
    ScriptTitle = '';
    end
    elseif utilities.is_set (Chapter) then -- |title= not set
    Title = Periodical; -- |encyclopedia= set and |article= set so map |encyclopedia= to |title=
    Periodical = ''; -- redundant so unset
    end
    end
    end
     
    -- special case for cite techreport.
    local ID = A['ID'];
    if (config.CitationClass == "techreport") then -- special case for cite techreport
    if utilities.is_set (A['Number']) then -- cite techreport uses 'number', which other citations alias to 'issue'
    if not utilities.is_set (ID) then -- can we use ID for the "number"?
    ID = A['Number']; -- yes, use it
    else -- ID has a value so emit error message
    table.insert( z.message_tail, { utilities.set_message ('err_redundant_parameters', {utilities.wrap_style ('parameter', 'id') .. ' and ' .. utilities.wrap_style ('parameter', 'number')}, true )});
    end
    end
    end
     
    -- Account for the oddity that is {{cite conference}}, before generation of COinS data.
    local ChapterLink -- = A['ChapterLink']; -- deprecated as a parameter but still used internally by cite episode
    local Conference = A['Conference'];
    local BookTitle = A['BookTitle'];
    local TransTitle_origin = A:ORIGIN ('TransTitle');
    if 'conference' == config.CitationClass then
    if utilities.is_set (BookTitle) then
    Chapter = Title;
    Chapter_origin = 'title';
    -- ChapterLink = TitleLink; -- |chapter-link= is deprecated
    ChapterURL = URL;
    ChapterUrlAccess = UrlAccess;
    ChapterURL_origin = URL_origin;
    URL_origin = '';
    ChapterFormat = Format;
    TransChapter = TransTitle;
    TransChapter_origin = TransTitle_origin;
    Title = BookTitle;
    Format = '';
    -- TitleLink = '';
    TransTitle = '';
    URL = '';
    end
    elseif 'speech' ~= config.CitationClass then
    Conference = ''; -- not cite conference or cite speech so make sure this is empty string
    end
    -- CS1/2 mode
    local Mode = is_valid_parameter_value (A['Mode'], A:ORIGIN('Mode'), cfg.keywords_lists['mode'], '');
    -- separator character and postscript
    local sepc, PostScript = set_style (Mode:lower(), A['PostScript'], config.CitationClass);
    -- controls capitalization of certain static text
    local use_lowercase = ( sepc == ',' );
    -- cite map oddities
    local Cartography = "";
    local Scale = "";
    local Sheet = A['Sheet'] or '';
    local Sheets = A['Sheets'] or '';
    if config.CitationClass == "map" then
    if utilities.is_set (Chapter) then
    table.insert( z.message_tail, { utilities.set_message ( 'err_redundant_parameters', {utilities.wrap_style ('parameter', 'map') .. ' and ' .. utilities.wrap_style ('parameter', Chapter_origin)}, true ) } ); -- add error message
    end
    Chapter = A['Map'];
    Chapter_origin = A:ORIGIN('Map');
    ChapterURL = A['MapURL'];
    ChapterURL_origin = A:ORIGIN('MapURL');
    TransChapter = A['TransMap'];
    ScriptChapter = A['ScriptMap']
    ScriptChapter_origin = A:ORIGIN('ScriptMap')
     
    ChapterUrlAccess = MapUrlAccess;
    ChapterFormat = A['MapFormat'];
     
    Cartography = A['Cartography'];
    if utilities.is_set ( Cartography ) then
    Cartography = sepc .. " " .. wrap_msg ('cartography', Cartography, use_lowercase);
    end
    Scale = A['Scale'];
    if utilities.is_set ( Scale ) then
    Scale = sepc .. " " .. Scale;
    end
    end
     
    -- Account for the oddities that are {{cite episode}} and {{cite serial}}, before generation of COinS data.
    local Series = A['Series'];
    if 'episode' == config.CitationClass or 'serial' == config.CitationClass then
    local SeriesLink = A['SeriesLink'];
     
    SeriesLink = link_title_ok (SeriesLink, A:ORIGIN ('SeriesLink'), Series, 'series'); -- check for wiki-markup in |series-link= or wiki-markup in |series= when |series-link= is set
     
    local Network = A['Network'];
    local Station = A['Station'];
    local s, n = {}, {};
    -- do common parameters first
    if utilities.is_set (Network) then table.insert(n, Network); end
    if utilities.is_set (Station) then table.insert(n, Station); end
    ID = table.concat(n, sepc .. ' ');
    if 'episode' == config.CitationClass then -- handle the oddities that are strictly {{cite episode}}
    local Season = A['Season'];
    local SeriesNumber = A['SeriesNumber'];
     
    if utilities.is_set (Season) and utilities.is_set (SeriesNumber) then -- these are mutually exclusive so if both are set
    table.insert( z.message_tail, { utilities.set_message ( 'err_redundant_parameters', {utilities.wrap_style ('parameter', 'season') .. ' and ' .. utilities.wrap_style ('parameter', 'seriesno')}, true ) } ); -- add error message
    SeriesNumber = ''; -- unset; prefer |season= over |seriesno=
    end
    -- assemble a table of parts concatenated later into Series
    if utilities.is_set (Season) then table.insert(s, wrap_msg ('season', Season, use_lowercase)); end
    if utilities.is_set (SeriesNumber) then table.insert(s, wrap_msg ('seriesnum', SeriesNumber, use_lowercase)); end
    if utilities.is_set (Issue) then table.insert(s, wrap_msg ('episode', Issue, use_lowercase)); end
    Issue = ''; -- unset because this is not a unique parameter
    Chapter = Title; -- promote title parameters to chapter
    ScriptChapter = ScriptTitle;
    ScriptChapter_origin = A:ORIGIN('ScriptTitle');
    ChapterLink = TitleLink; -- alias |episode-link=
    TransChapter = TransTitle;
    ChapterURL = URL;
    ChapterUrlAccess = UrlAccess;
    ChapterURL_origin = URL_origin;
    Title = Series; -- promote series to title
    TitleLink = SeriesLink;
    Series = table.concat(s, sepc .. ' '); -- this is concatenation of season, seriesno, episode number
     
    if utilities.is_set (ChapterLink) and not utilities.is_set (ChapterURL) then -- link but not URL
    Chapter = utilities.make_wikilink (ChapterLink, Chapter);
    elseif utilities.is_set (ChapterLink) and utilities.is_set (ChapterURL) then -- if both are set, URL links episode;
    Series = utilities.make_wikilink (ChapterLink, Series);
    end
    URL = ''; -- unset
    TransTitle = '';
    ScriptTitle = '';
    else -- now oddities that are cite serial
    Issue = ''; -- unset because this parameter no longer supported by the citation/core version of cite serial
    Chapter = A['Episode']; -- TODO: make |episode= available to cite episode someday?
    if utilities.is_set (Series) and utilities.is_set (SeriesLink) then
    Series = utilities.make_wikilink (SeriesLink, Series);
    end
    Series = utilities.wrap_style ('italic-title', Series); -- series is italicized
    end
    end
    -- end of {{cite episode}} stuff
     
    -- handle type parameter for those CS1 citations that have default values
    local TitleType = A['TitleType'];
    local Degree = A['Degree'];
    if utilities.in_array (config.CitationClass, {"AV-media-notes", "interview", "mailinglist", "map", "podcast", "pressrelease", "report", "techreport", "thesis"}) then
    TitleType = set_titletype (config.CitationClass, TitleType);
    if utilities.is_set (Degree) and "Thesis" == TitleType then -- special case for cite thesis
    TitleType = Degree .. ' ' .. cfg.title_types ['thesis']:lower();
    end
    end
     
    if utilities.is_set (TitleType) then -- if type parameter is specified
    TitleType = utilities.substitute ( cfg.messages['type'], TitleType); -- display it in parentheses
    -- TODO: Hack on TitleType to fix bunched parentheses problem
    end
     
    -- legacy: promote PublicationDate to Date if neither Date nor Year are set.
    local Date = A['Date'];
    local Date_origin; -- to hold the name of parameter promoted to Date; required for date error messaging
    local PublicationDate = A['PublicationDate'];
    local Year = A['Year'];
     
    if not utilities.is_set (Date) then
    Date = Year; -- promote Year to Date
    Year = nil; -- make nil so Year as empty string isn't used for CITEREF
    if not utilities.is_set (Date) and utilities.is_set (PublicationDate) then -- use PublicationDate when |date= and |year= are not set
    Date = PublicationDate; -- promote PublicationDate to Date
    PublicationDate = ''; -- unset, no longer needed
    Date_origin = A:ORIGIN('PublicationDate'); -- save the name of the promoted parameter
    else
    Date_origin = A:ORIGIN('Year'); -- save the name of the promoted parameter
    end
    else
    Date_origin = A:ORIGIN('Date'); -- not a promotion; name required for error messaging
    end
     
    if PublicationDate == Date then PublicationDate = ''; end -- if PublicationDate is same as Date, don't display in rendered citation
     
    --[[
    Go test all of the date-holding parameters for valid MOS:DATE format and make sure that dates are real dates. This must be done before we do COinS because here is where
    we get the date used in the metadata.
    Date validation supporting code is in Module:Citation/CS1/Date_validation
    ]]
     
    local DF = is_valid_parameter_value (A['DF'], A:ORIGIN('DF'), cfg.keywords_lists['df'], '');
    if not utilities.is_set (DF) then
    DF = cfg.global_df; -- local |df= if present overrides global df set by {{use xxx date}} template
    end
     
    local ArchiveURL;
    local ArchiveDate;
    local ArchiveFormat = A['ArchiveFormat'];
     
    ArchiveURL, ArchiveDate = archive_url_check (A['ArchiveURL'], A['ArchiveDate'])
    ArchiveFormat = style_format (ArchiveFormat, ArchiveURL, 'archive-format', 'archive-url');
    ArchiveURL, ArchiveDate = is_unique_archive_url (ArchiveURL, URL, ChapterURL, A:ORIGIN('ArchiveURL'), ArchiveDate); -- add error message when URL or ChapterURL == ArchiveURL
     
    local AccessDate = A['AccessDate'];
    local LayDate = A['LayDate'];
    local COinS_date = {}; -- holds date info extracted from |date= for the COinS metadata by Module:Date verification
    local DoiBroken = A['DoiBroken'];
    local Embargo = A['Embargo'];
    local anchor_year; -- used in the CITEREF identifier
    do -- create defined block to contain local variables error_message, date_parameters_list, mismatch
    local error_message = '';
    -- AirDate has been promoted to Date so not necessary to check it
    local date_parameters_list = {
    ['access-date'] = {val = AccessDate, name = A:ORIGIN ('AccessDate')},
    ['archive-date'] = {val = ArchiveDate, name = A:ORIGIN ('ArchiveDate')},
    ['date'] = {val = Date, name = Date_origin},
    ['doi-broken-date'] = {val = DoiBroken, name = A:ORIGIN ('DoiBroken')},
    ['pmc-embargo-date'] = {val = Embargo, name = A:ORIGIN ('Embargo')},
    ['lay-date'] = {val = LayDate, name = A:ORIGIN ('LayDate')},
    ['publication-date'] = {val = PublicationDate, name = A:ORIGIN ('PublicationDate')},
    ['year'] = {val = Year, name = A:ORIGIN ('Year')},
    };
     
    local error_list = {};
    anchor_year, Embargo = validation.dates(date_parameters_list, COinS_date, error_list);
     
    -- start temporary Julian / Gregorian calendar uncertainty categorization
    if COinS_date.inter_cal_cat then
    utilities.add_prop_cat ('jul_greg_uncertainty');
    end
    -- end temporary Julian / Gregorian calendar uncertainty categorization
     
    if utilities.is_set (Year) and utilities.is_set (Date) then -- both |date= and |year= not normally needed;
    validation.year_date_check (Year, A:ORIGIN ('Year'), Date, A:ORIGIN ('Date'), error_list);
    end
    if 0 == #error_list then -- error free dates only; 0 when error_list is empty
    local modified = false; -- flag
    if validation.edtf_transform (date_parameters_list) then -- edtf dates to MOS compliant format
    modified = true;
    end
     
    if utilities.is_set (DF) then -- if we need to reformat dates
    modified = validation.reformat_dates (date_parameters_list, DF); -- reformat to DF format, use long month names if appropriate
    end
     
    if true == validation.date_hyphen_to_dash (date_parameters_list) then -- convert hyphens to dashes where appropriate
    modified = true;
    utilities.set_message ('maint_date_format'); -- hyphens were converted so add maint category
    end
    -- for those wikis that can and want to have English date names translated to the local language,
    -- uncomment the next three lines.  Not supported by en.wiki (for obvious reasons)
    -- set validation.date_name_xlate() second argument to true to translate English digits to local digits (will translate ymd dates)
    -- if validation.date_name_xlate (date_parameters_list, false) then
    -- modified = true;
    -- end
     
    if modified then -- if the date_parameters_list values were modified
    AccessDate = date_parameters_list['access-date'].val; -- overwrite date holding parameters with modified values
    ArchiveDate = date_parameters_list['archive-date'].val;
    Date = date_parameters_list['date'].val;
    DoiBroken = date_parameters_list['doi-broken-date'].val;
    LayDate = date_parameters_list['lay-date'].val;
    PublicationDate = date_parameters_list['publication-date'].val;
    end
    else
    table.insert (z.message_tail, {utilities.set_message ('err_bad_date', {utilities.make_sep_list (#error_list, error_list)}, true)}); -- add this error message
    end
    end -- end of do
     
    local ID_list = {}; -- sequence table of rendered identifiers
    local ID_list_coins = {}; -- table of identifiers and their values from args; key is same as cfg.id_handlers's key
    local Class = A['Class']; -- arxiv class identifier
    local ID_support = {
    {A['ASINTLD'], 'ASIN', 'err_asintld_missing_asin', A:ORIGIN ('ASINTLD')},
    {DoiBroken, 'DOI', 'err_doibroken_missing_doi', A:ORIGIN ('DoiBroken')},
    {Embargo, 'PMC', 'err_embargo_missing_pmc', A:ORIGIN ('Embargo')},
    }
     
    ID_list, ID_list_coins = identifiers.identifier_lists_get (args, {DoiBroken = DoiBroken, ASINTLD = A['ASINTLD'], Embargo = Embargo, Class = Class}, ID_support);
     
    -- Account for the oddities that are {{cite arxiv}}, {{cite biorxiv}}, {{cite citeseerx}}, {{cite ssrn}}, before generation of COinS data.
    if utilities.in_array (config.CitationClass, whitelist.preprint_template_list) then
    if not utilities.is_set (ID_list_coins[config.CitationClass:upper()]) then -- |arxiv= or |eprint= required for cite arxiv; |biorxiv= & |citeseerx= required for their templates
    table.insert (z.message_tail, {utilities.set_message ('err_' .. config.CitationClass .. '_missing', {}, true)}); -- add error message
    end
     
    Periodical = ({['arxiv'] = 'arXiv', ['biorxiv'] = 'bioRxiv', ['citeseerx'] = 'CiteSeerX', ['ssrn'] = 'Social Science Research Network'})[config.CitationClass];
    end
     
    -- Link the title of the work if no |url= was provided, but we have a |pmc= or a |doi= with |doi-access=free
     
    if config.CitationClass == "journal" and not utilities.is_set (URL) and not utilities.is_set (TitleLink) and not utilities.in_array (cfg.keywords_xlate[Title], {'off', 'none'}) then -- TODO: remove 'none' once existing citations have been switched to 'off', so 'none' can be used as token for "no title" instead
    if 'none' ~= cfg.keywords_xlate[auto_select] then -- if auto-linking not disabled
    if identifiers.auto_link_urls[auto_select] then -- manual selection
    URL = identifiers.auto_link_urls[auto_select]; -- set URL to be the same as identifier's external link
    URL_origin = cfg.id_handlers[auto_select:upper()].parameters[1]; -- set URL_origin to parameter name for use in error message if citation is missing a |title=
    elseif identifiers.auto_link_urls['pmc'] then -- auto-select PMC
    URL = identifiers.auto_link_urls['pmc']; -- set URL to be the same as the PMC external link if not embargoed
    URL_origin = cfg.id_handlers['PMC'].parameters[1]; -- set URL_origin to parameter name for use in error message if citation is missing a |title=
    elseif identifiers.auto_link_urls['doi'] then -- auto-select DOI
    URL = identifiers.auto_link_urls['doi'];
    URL_origin = cfg.id_handlers['DOI'].parameters[1];
    end
    end
     
    if utilities.is_set (URL) and utilities.is_set (AccessDate) then -- access date requires |url=; identifier-created URL is not |url=
    table.insert( z.message_tail, { utilities.set_message ( 'err_accessdate_missing_url', {}, true ) } ); -- add an error message
    AccessDate = ''; -- unset
    end
    end
     
    -- At this point fields may be nil if they weren't specified in the template use.  We can use that fact.
    -- Test if citation has no title
    if not utilities.is_set (Title) and not utilities.is_set (TransTitle) and not utilities.is_set (ScriptTitle) then -- has special case for cite episode
    table.insert( z.message_tail, { utilities.set_message ( 'err_citation_missing_title', {'episode' == config.CitationClass and 'series' or 'title'}, true ) } );
    end
     
    if utilities.in_array (cfg.keywords_xlate[Title], {'off', 'none'}) and
    utilities.in_array (config.CitationClass, {'journal', 'citation'}) and
    (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical)) and
    ('journal' == Periodical_origin or 'script-journal' == ScriptPeriodical_origin) then -- special case for journal cites
    Title = ''; -- set title to empty string
    utilities.set_message ('maint_untitled'); -- add maint cat
    end
     
    check_for_url ({ -- add error message when any of these parameters hold a URL
    ['title'] = Title,
    [A:ORIGIN('Chapter')] = Chapter,
    [Periodical_origin] = Periodical,
    [PublisherName_origin] = PublisherName
    });
     
    -- COinS metadata (see <http://ocoins.info/>) for automated parsing of citation information.
    -- handle the oddity that is cite encyclopedia and {{citation |encyclopedia=something}}. Here we presume that
    -- when Periodical, Title, and Chapter are all set, then Periodical is the book (encyclopedia) title, Title
    -- is the article title, and Chapter is a section within the article.  So, we remap
    local coins_chapter = Chapter; -- default assuming that remapping not required
    local coins_title = Title; -- et tu
    if 'encyclopaedia' == config.CitationClass or ('citation' == config.CitationClass and utilities.is_set (Encyclopedia)) then
    if utilities.is_set (Chapter) and utilities.is_set (Title) and utilities.is_set (Periodical) then -- if all are used then
    coins_chapter = Title; -- remap
    coins_title = Periodical;
    end
    end
    local coins_author = a; -- default for coins rft.au
    if 0 < #c then -- but if contributor list
    coins_author = c; -- use that instead
    end
    local QuotePage = A['QuotePage'];
    local QuotePages = hyphen_to_dash (A['QuotePages']);
     
    -- this is the function call to COinS()
    local OCinSoutput = metadata.COinS({
    ['Periodical'] = utilities.strip_apostrophe_markup (Periodical), -- no markup in the metadata
    ['Encyclopedia'] = Encyclopedia, -- just a flag; content ignored by ~/COinS
    ['Chapter'] = metadata.make_coins_title (coins_chapter, ScriptChapter), -- Chapter and ScriptChapter stripped of bold / italic wiki-markup
    ['Degree'] = Degree; -- cite thesis only
    ['Title'] = metadata.make_coins_title (coins_title, ScriptTitle), -- Title and ScriptTitle stripped of bold / italic wiki-markup
    ['PublicationPlace'] = PublicationPlace,
    ['Date'] = COinS_date.rftdate, -- COinS_date has correctly formatted date if Date is valid;
    ['Season'] = COinS_date.rftssn,
    ['Quarter'] = COinS_date.rftquarter,
    ['Chron'] =  COinS_date.rftchron or (not COinS_date.rftdate and Date) or '', -- chron but if not set and invalid date format use Date; keep this last bit?
    ['Series'] = Series,
    ['Volume'] = Volume,
    ['Issue'] = Issue,
    ['Pages'] = coins_pages or metadata.get_coins_pages (first_set ({Sheet, Sheets, Page, Pages, At, QuotePage, QuotePages}, 7)), -- pages stripped of external links
    ['Edition'] = Edition,
    ['PublisherName'] = PublisherName or Newsgroup, -- any apostrophe markup already removed from PublisherName
    ['URL'] = first_set ({ChapterURL, URL}, 2),
    ['Authors'] = coins_author,
    ['ID_list'] = ID_list_coins,
    ['RawPage'] = this_page.prefixedText,
    }, config.CitationClass);
     
    -- Account for the oddities that are {{cite arxiv}}, {{cite biorxiv}}, {{cite citeseerx}}, and {{cite ssrn}} AFTER generation of COinS data.
    if utilities.in_array (config.CitationClass, whitelist.preprint_template_list) then -- we have set rft.jtitle in COinS to arXiv, bioRxiv, CiteSeerX, or ssrn now unset so it isn't displayed
    Periodical = ''; -- periodical not allowed in these templates; if article has been published, use cite journal
    end
     
    -- special case for cite newsgroup.  Do this after COinS because we are modifying Publishername to include some static text
    if 'newsgroup' == config.CitationClass and utilities.is_set (Newsgroup) then
    PublisherName = utilities.substitute (cfg.messages['newsgroup'], external_link( 'news:' .. Newsgroup, Newsgroup, Newsgroup_origin, nil ));
    end
     
    local Editors;
    local EditorCount; -- used only for choosing {ed.) or (eds.) annotation at end of editor name-list
    local Contributors; -- assembled contributors name list
    local contributor_etal;
    local Translators; -- assembled translators name list
    local translator_etal;
    local t = {}; -- translators list from |translator-lastn= / translator-firstn= pairs
    t = extract_names (args, 'TranslatorList'); -- fetch translator list from |translatorn= / |translator-lastn=, -firstn=, -linkn=, -maskn=
    local Interviewers;
    local interviewers_list = {};
    interviewers_list = extract_names (args, 'InterviewerList'); -- process preferred interviewers parameters
    local interviewer_etal;
    -- Now perform various field substitutions.
    -- We also add leading spaces and surrounding markup and punctuation to the
    -- various parts of the citation, but only when they are non-nil.
    do
    local last_first_list;
    local control = {
    format = NameListStyle, -- empty string or 'vanc'
    maximum = nil, -- as if display-authors or display-editors not set
    mode = Mode
    };
     
    do -- do editor name list first because the now unsupported coauthors used to modify control table
    control.maximum , editor_etal = get_display_names (A['DisplayEditors'], #e, 'editors', editor_etal, A:ORIGIN ('DisplayEditors'));
    Editors, EditorCount = list_people (control, e, editor_etal);
     
    if 1 == EditorCount and (true == editor_etal or 1 < #e) then -- only one editor displayed but includes etal then
    EditorCount = 2; -- spoof to display (eds.) annotation
    end
    end
    do -- now do interviewers
    control.maximum, interviewer_etal = get_display_names (A['DisplayInterviewers'], #interviewers_list, 'interviewers', interviewer_etal, A:ORIGIN ('DisplayInterviewers'));
    Interviewers = list_people (control, interviewers_list, interviewer_etal);
    end
    do -- now do translators
    control.maximum, translator_etal = get_display_names (A['DisplayTranslators'], #t, 'translators', translator_etal, A:ORIGIN ('DisplayTranslators'));
    Translators = list_people (control, t, translator_etal);
    end
    do -- now do contributors
    control.maximum, contributor_etal = get_display_names (A['DisplayContributors'], #c, 'contributors', contributor_etal, A:ORIGIN ('DisplayContributors'));
    Contributors = list_people (control, c, contributor_etal);
    end
    do -- now do authors
    control.maximum, author_etal = get_display_names (A['DisplayAuthors'], #a, 'authors', author_etal, A:ORIGIN ('DisplayAuthors'));
     
    last_first_list = list_people (control, a, author_etal);
     
    if utilities.is_set (Authors) then
    Authors, author_etal = name_has_etal (Authors, author_etal, false, 'authors'); -- find and remove variations on et al.
    if author_etal then
    Authors = Authors .. ' ' .. cfg.messages['et al']; -- add et al. to authors parameter
    end
    else
    Authors = last_first_list; -- either an author name list or an empty string
    end
    end -- end of do
    if utilities.is_set (Authors) and utilities.is_set (Collaboration) then
    Authors = Authors .. ' (' .. Collaboration .. ')'; -- add collaboration after et al.
    end
     
    end
     
    local ConferenceFormat = A['ConferenceFormat'];
    local ConferenceURL = A['ConferenceURL'];
    ConferenceFormat = style_format (ConferenceFormat, ConferenceURL, 'conference-format', 'conference-url');
    Format = style_format (Format, URL, 'format', 'url');
     
    -- special case for chapter format so no error message or cat when chapter not supported
    if not (utilities.in_array (config.CitationClass, {'web', 'news', 'journal', 'magazine', 'pressrelease', 'podcast', 'newsgroup', 'arxiv', 'biorxiv', 'citeseerx', 'ssrn'}) or
    ('citation' == config.CitationClass and (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical)) and not utilities.is_set (Encyclopedia))) then
    ChapterFormat = style_format (ChapterFormat, ChapterURL, 'chapter-format', 'chapter-url');
    end
     
    if not utilities.is_set (URL) then
    if utilities.in_array (config.CitationClass, {"web", "podcast", "mailinglist"}) or -- |url= required for cite web, cite podcast, and cite mailinglist
    ('citation' == config.CitationClass and ('website' == Periodical_origin or 'script-website' == ScriptPeriodical_origin)) then -- and required for {{citation}} with |website= or |script-website=
    table.insert( z.message_tail, { utilities.set_message ( 'err_cite_web_url', {}, true ) } );
    end
    -- do we have |accessdate= without either |url= or |chapter-url=?
    if utilities.is_set (AccessDate) and not utilities.is_set (ChapterURL) then -- ChapterURL may be set when URL is not set;
    table.insert( z.message_tail, { utilities.set_message ( 'err_accessdate_missing_url', {}, true ) } );
    AccessDate = '';
    end
    end
     
    local UrlStatus = is_valid_parameter_value (A['UrlStatus'], A:ORIGIN('UrlStatus'), cfg.keywords_lists['url-status'], '');
    local OriginalURL
    local OriginalURL_origin
    local OriginalFormat
    local OriginalAccess;
    UrlStatus = UrlStatus:lower(); -- used later when assembling archived text
    if utilities.is_set ( ArchiveURL ) then
    if utilities.is_set (ChapterURL) then -- if chapter-url= is set apply archive url to it
    OriginalURL = ChapterURL; -- save copy of source chapter's url for archive text
    OriginalURL_origin = ChapterURL_origin; -- name of |chapter-url= parameter for error messages
    OriginalFormat = ChapterFormat; -- and original |chapter-format=
     
    if 'live' ~= UrlStatus then
    ChapterURL = ArchiveURL -- swap-in the archive's URL
    ChapterURL_origin = A:ORIGIN('ArchiveURL') -- name of |archive-url= parameter for error messages
    ChapterFormat = ArchiveFormat or ''; -- swap in archive's format
    ChapterUrlAccess = nil; -- restricted access levels do not make sense for archived URLs
    end
    elseif utilities.is_set (URL) then
    OriginalURL = URL; -- save copy of original source URL
    OriginalURL_origin = URL_origin; -- name of URL parameter for error messages
    OriginalFormat = Format; -- and original |format=
    OriginalAccess = UrlAccess;
     
    if 'live' ~= UrlStatus then -- if URL set then |archive-url= applies to it
    URL = ArchiveURL -- swap-in the archive's URL
    URL_origin = A:ORIGIN('ArchiveURL') -- name of archive URL parameter for error messages
    Format = ArchiveFormat or ''; -- swap in archive's format
    UrlAccess = nil; -- restricted access levels do not make sense for archived URLs
    end
    end
    end
     
    if utilities.in_array (config.CitationClass, {'web', 'news', 'journal', 'magazine', 'pressrelease', 'podcast', 'newsgroup', 'arxiv', 'biorxiv', 'citeseerx', 'ssrn'}) or -- if any of the 'periodical' cites except encyclopedia
    ('citation' == config.CitationClass and (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical)) and not utilities.is_set (Encyclopedia)) then
    local chap_param;
    if utilities.is_set (Chapter) then -- get a parameter name from one of these chapter related meta-parameters
    chap_param = A:ORIGIN ('Chapter')
    elseif utilities.is_set (TransChapter) then
    chap_param = A:ORIGIN ('TransChapter')
    elseif utilities.is_set (ChapterURL) then
    chap_param = A:ORIGIN ('ChapterURL')
    elseif utilities.is_set (ScriptChapter) then
    chap_param = ScriptChapter_origin;
    else utilities.is_set (ChapterFormat)
    chap_param = A:ORIGIN ('ChapterFormat')
    end
     
    if utilities.is_set (chap_param) then -- if we found one
    table.insert( z.message_tail, { utilities.set_message ( 'err_chapter_ignored', {chap_param}, true ) } ); -- add error message
    Chapter = ''; -- and set them to empty string to be safe with concatenation
    TransChapter = '';
    ChapterURL = '';
    ScriptChapter = '';
    ChapterFormat = '';
    end
    else -- otherwise, format chapter / article title
    local no_quotes = false; -- default assume that we will be quoting the chapter parameter value
    if utilities.is_set (Contribution) and 0 < #c then -- if this is a contribution with contributor(s)
    if utilities.in_array (Contribution:lower(), cfg.keywords_lists.contribution) then -- and a generic contribution title
    no_quotes = true; -- then render it unquoted
    end
    end
     
    Chapter = format_chapter_title (ScriptChapter, ScriptChapter_origin, Chapter, Chapter_origin, TransChapter, TransChapter_origin, ChapterURL, ChapterURL_origin, no_quotes, ChapterUrlAccess); -- Contribution is also in Chapter
    if utilities.is_set (Chapter) then
    Chapter = Chapter .. ChapterFormat ;
    if 'map' == config.CitationClass and utilities.is_set (TitleType) then
    Chapter = Chapter .. ' ' .. TitleType; -- map annotation here; not after title
    end
    Chapter = Chapter .. sepc .. ' ';
    elseif utilities.is_set (ChapterFormat) then -- |chapter= not set but |chapter-format= is so ...
    Chapter = ChapterFormat .. sepc .. ' '; -- ... ChapterFormat has error message, we want to see it
    end
    end
     
    -- Format main title
    local plain_title = false;
    local accept_title;
    Title, accept_title = utilities.has_accept_as_written (Title, true); -- remove accept-this-as-written markup when it wraps all of <Title>
    if accept_title and ('' == Title) then -- only support forced empty for now "(())"
    Title = cfg.messages['notitle']; -- replace by predefined "No title" message
    -- TODO: utilities.set_message ( 'err_redundant_parameters', ...); -- issue proper error message instead of muting
    ScriptTitle = ''; -- just mute for now
    TransTitle = ''; -- just mute for now
    plain_title = true; -- suppress text decoration for descriptive title
    utilities.set_message ('maint_untitled'); -- add maint cat
    end
     
    if not accept_title then -- <Title> not wrapped in accept-as-written markup
    if '...' == Title:sub (-3) then -- if ellipsis is the last three characters of |title=
    Title = Title:gsub ('(%.%.%.)%.+$', '%1'); -- limit the number of dots to three
    elseif not mw.ustring.find (Title, '%.%s*%a%.$') and -- end of title is not a 'dot-(optional space-)letter-dot' initialism ...
    not mw.ustring.find (Title, '%s+%a%.$') then -- ...and not a 'space-letter-dot' initial (''Allium canadense'' L.)
    Title = mw.ustring.gsub(Title, '%' .. sepc .. '$', ''); -- remove any trailing separator character; sepc and ms.ustring() here for languages that use multibyte separator characters
    end
     
    if utilities.is_set (ArchiveURL) and is_archived_copy (Title) then
    utilities.set_message ('maint_archived_copy'); -- add maintenance category before we modify the content of Title
    end
     
    if is_generic_title (Title) then
    table.insert (z.message_tail, {utilities.set_message ( 'err_generic_title', {}, true ) } ); -- set an error message
    end
    end
     
    if (not plain_title) and (utilities.in_array (config.CitationClass, {'web', 'news', 'journal', 'magazine', 'pressrelease', 'podcast', 'newsgroup', 'mailinglist', 'interview', 'arxiv', 'biorxiv', 'citeseerx', 'ssrn'}) or
    ('citation' == config.CitationClass and (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical)) and not utilities.is_set (Encyclopedia)) or
    ('map' == config.CitationClass and (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical)))) then -- special case for cite map when the map is in a periodical treat as an article
    Title = kern_quotes (Title); -- if necessary, separate title's leading and trailing quote marks from module provided quote marks
    Title = utilities.wrap_style ('quoted-title', Title);
    Title = script_concatenate (Title, ScriptTitle, 'script-title'); -- <bdi> tags, lang attribute, categorization, etc.; must be done after title is wrapped
    TransTitle = utilities.wrap_style ('trans-quoted-title', TransTitle );
    elseif plain_title or ('report' == config.CitationClass) then -- no styling for cite report and descriptive titles (otherwise same as above)
    Title = script_concatenate (Title, ScriptTitle, 'script-title'); -- <bdi> tags, lang attribute, categorization, etc.; must be done after title is wrapped
    TransTitle = utilities.wrap_style ('trans-quoted-title', TransTitle ); -- for cite report, use this form for trans-title
    else
    Title = utilities.wrap_style ('italic-title', Title);
    Title = script_concatenate (Title, ScriptTitle, 'script-title'); -- <bdi> tags, lang attribute, categorization, etc.; must be done after title is wrapped
    TransTitle = utilities.wrap_style ('trans-italic-title', TransTitle);
    end
     
    local TransError = "";
    if utilities.is_set (TransTitle) then
    if utilities.is_set (Title) then
    TransTitle = " " .. TransTitle;
    else
    TransError = " " .. utilities.set_message ( 'err_trans_missing_title', {'title'} );
    end
    end
     
    if utilities.is_set (Title) then -- TODO: is this the right place to be making Wikisource URLs?
    if utilities.is_set (TitleLink) and utilities.is_set (URL) then
    table.insert( z.message_tail, { utilities.set_message ( 'err_wikilink_in_url', {}, true ) } ); -- set an error message because we can't have both
    TitleLink = ''; -- unset
    end
    if not utilities.is_set (TitleLink) and utilities.is_set (URL) then
    Title = external_link (URL, Title, URL_origin, UrlAccess) .. TransTitle .. TransError .. Format;
    URL = ''; -- unset these because no longer needed
    Format = "";
    elseif utilities.is_set (TitleLink) and not utilities.is_set (URL) then
    local ws_url;
    ws_url = wikisource_url_make (TitleLink); -- ignore ws_label return; not used here
    if ws_url then
    Title = external_link (ws_url, Title .. '&nbsp;', 'ws link in title-link'); -- space char after Title to move icon away from italic text; TODO: a better way to do this?
    Title = utilities.substitute (cfg.presentation['interwiki-icon'], {cfg.presentation['class-wikisource'], TitleLink, Title});
    Title = Title .. TransTitle .. TransError;
    else
    Title = utilities.make_wikilink (TitleLink, Title) .. TransTitle .. TransError;
    end
    else
    local ws_url, ws_label, L; -- Title has italic or quote markup by the time we get here which causes is_wikilink() to return 0 (not a wikilink)
    ws_url, ws_label, L = wikisource_url_make (Title:gsub('^[\'"]*(.-)[\'"]*$', '%1')); -- make ws URL from |title= interwiki link (strip italic or quote markup); link portion L becomes tooltip label
    if ws_url then
    Title = Title:gsub ('%b[]', ws_label); -- replace interwiki link with ws_label to retain markup
    Title = external_link (ws_url, Title .. '&nbsp;', 'ws link in title'); -- space char after Title to move icon away from italic text; TODO: a better way to do this?
    Title = utilities.substitute (cfg.presentation['interwiki-icon'], {cfg.presentation['class-wikisource'], L, Title});
    Title = Title .. TransTitle .. TransError;
    else
    Title = Title .. TransTitle .. TransError;
    end
    end
    else
    Title = TransTitle .. TransError;
    end
     
    if utilities.is_set (Place) then
    Place = " " .. wrap_msg ('written', Place, use_lowercase) .. sepc .. " ";
    end
     
    local ConferenceURL_origin = A:ORIGIN('ConferenceURL'); -- get name of parameter that holds ConferenceURL
    if utilities.is_set (Conference) then
    if utilities.is_set (ConferenceURL) then
    Conference = external_link( ConferenceURL, Conference, ConferenceURL_origin, nil );
    end
    Conference = sepc .. " " .. Conference .. ConferenceFormat;
    elseif utilities.is_set (ConferenceURL) then
    Conference = sepc .. " " .. external_link( ConferenceURL, nil, ConferenceURL_origin, nil );
    end
     
    local Position = '';
    if not utilities.is_set (Position) then
    local Minutes = A['Minutes'];
    local Time = A['Time'];
     
    if utilities.is_set (Minutes) then
    if utilities.is_set (Time) then
    table.insert( z.message_tail, { utilities.set_message ( 'err_redundant_parameters', {utilities.wrap_style ('parameter', 'minutes') .. ' and ' .. utilities.wrap_style ('parameter', 'time')}, true ) } );
    end
    Position = " " .. Minutes .. " " .. cfg.messages['minutes'];
    else
    if utilities.is_set (Time) then
    local TimeCaption = A['TimeCaption']
    if not utilities.is_set (TimeCaption) then
    TimeCaption = cfg.messages['event'];
    if sepc ~= '.' then
    TimeCaption = TimeCaption:lower();
    end
    end
    Position = " " .. TimeCaption .. " " .. Time;
    end
    end
    else
    Position = " " .. Position;
    At = '';
    end
     
    Page, Pages, Sheet, Sheets = format_pages_sheets (Page, Pages, Sheet, Sheets, config.CitationClass, Periodical_origin, sepc, NoPP, use_lowercase);
     
    At = utilities.is_set (At) and (sepc .. " " .. At) or "";
    Position = utilities.is_set (Position) and (sepc .. " " .. Position) or "";
    if config.CitationClass == 'map' then
    local Sections = A['Sections']; -- Section (singular) is an alias of Chapter so set earlier
    local Inset = A['Inset'];
    if utilities.is_set ( Inset ) then
    Inset = sepc .. " " .. wrap_msg ('inset', Inset, use_lowercase);
    end
     
    if utilities.is_set ( Sections ) then
    Section = sepc .. " " .. wrap_msg ('sections', Sections, use_lowercase);
    elseif utilities.is_set ( Section ) then
    Section = sepc .. " " .. wrap_msg ('section', Section, use_lowercase);
    end
    At = At .. Inset .. Section;
    end
     
    local Others = A['Others'];
    if utilities.is_set (Others) and 0 == #a and 0 == #e then -- add maint cat when |others= has value and used without |author=, |editor=
    if config.CitationClass == "AV-media-notes"
    or config.CitationClass == "audio-visual" then -- special maint for AV/M which has a lot of 'false' positives right now
    utilities.set_message ('maint_others_avm')
    else
    utilities.set_message ('maint_others');
    end
    end
    Others = utilities.is_set (Others) and (sepc .. " " .. Others) or "";
    if utilities.is_set (Translators) then
    Others = safe_join ({sepc .. ' ', wrap_msg ('translated', Translators, use_lowercase), Others}, sepc);
    end
    if utilities.is_set (Interviewers) then
    Others = safe_join ({sepc .. ' ', wrap_msg ('interview', Interviewers, use_lowercase), Others}, sepc);
    end
    local TitleNote = A['TitleNote'];
    TitleNote = utilities.is_set (TitleNote) and (sepc .. " " .. TitleNote) or "";
    if utilities.is_set (Edition) then
    if Edition:match ('%f[%a][Ee]d%n?%.?$') or Edition:match ('%f[%a][Ee]dition$') then -- Ed, ed, Ed., ed., Edn, edn, Edn., edn.
    table.insert( z.message_tail, { utilities.set_message ( 'err_extra_text_edition')}); -- add error
    end
    Edition = " " .. wrap_msg ('edition', Edition);
    else
    Edition = '';
    end
     
    Series = utilities.is_set (Series) and wrap_msg ('series', {sepc, Series}) or ""; -- not the same as SeriesNum
    local Agency = A['Agency'];
    Agency = utilities.is_set (Agency) and wrap_msg ('agency', {sepc, Agency}) or "";
    Volume = format_volume_issue (Volume, Issue, config.CitationClass, Periodical_origin, sepc, use_lowercase);
     
    if utilities.is_set (AccessDate) then
    local retrv_text = " " .. cfg.messages['retrieved']
     
    AccessDate = nowrap_date (AccessDate); -- wrap in nowrap span if date in appropriate format
    if (sepc ~= ".") then retrv_text = retrv_text:lower() end -- if mode is cs2, lower case
    AccessDate = utilities.substitute (retrv_text, AccessDate); -- add retrieved text
     
    AccessDate = utilities.substitute (cfg.presentation['accessdate'], {sepc, AccessDate}); -- allow editors to hide accessdates
    end
    if utilities.is_set (ID) then ID = sepc .. " " .. ID; end
    local Docket = A['Docket'];
      if "thesis" == config.CitationClass and utilities.is_set (Docket) then
    ID = sepc .. " Docket " .. Docket .. ID;
    end
      if "report" == config.CitationClass and utilities.is_set (Docket) then -- for cite report when |docket= is set
    ID = sepc .. ' ' .. Docket; -- overwrite ID even if |id= is set
    end
     
    if utilities.is_set (URL) then
    URL = " " .. external_link( URL, nil, URL_origin, UrlAccess );
    end
     
    local Quote = A['Quote'];
    local TransQuote = A['TransQuote'];
    local ScriptQuote = A['ScriptQuote'];
    if utilities.is_set (Quote) or utilities.is_set (TransQuote) or utilities.is_set (ScriptQuote) then
     
    if utilities.is_set (Quote) then
    if Quote:sub(1, 1) == '"' and Quote:sub(-1, -1) == '"' then -- if first and last characters of quote are quote marks
    Quote = Quote:sub(2, -2); -- strip them off
    end
    end
     
    Quote = utilities.wrap_style ('quoted-text', Quote ); -- wrap in <q>...</q> tags
    if utilities.is_set (ScriptQuote) then
    Quote = script_concatenate (Quote, ScriptQuote, 'script-quote'); -- <bdi> tags, lang attribute, categorization, etc.; must be done after quote is wrapped
    end
     
    if utilities.is_set (TransQuote) then
    if TransQuote:sub(1, 1) == '"' and TransQuote:sub(-1, -1) == '"' then -- if first and last characters of |trans-quote are quote marks
    TransQuote = TransQuote:sub(2, -2); -- strip them off
    end
    Quote = Quote .. " " .. utilities.wrap_style ('trans-quoted-title', TransQuote );
    end
     
    if utilities.is_set (QuotePage) or utilities.is_set (QuotePages) then -- add page prefix
    local quote_prefix = '';
    if utilities.is_set (QuotePage) then
    extra_text_in_page_check (QuotePage, 'quote-page'); -- add to maint cat if |quote-page= value begins with what looks like p., pp., etc.
    if not NoPP then
    quote_prefix = utilities.substitute (cfg.messages['p-prefix'], {sepc, QuotePage}), '', '', '';
    else
    quote_prefix = utilities.substitute (cfg.messages['nopp'], {sepc, QuotePage}), '', '', '';
    end
    elseif utilities.is_set (QuotePages) then
    extra_text_in_page_check (QuotePages, 'quote-pages'); -- add to maint cat if |quote-pages= value begins with what looks like p., pp., etc.
    if tonumber(QuotePages) ~= nil and not NoPP then -- if only digits, assume single page
    quote_prefix = utilities.substitute (cfg.messages['p-prefix'], {sepc, QuotePages}), '', '';
    elseif not NoPP then
    quote_prefix = utilities.substitute (cfg.messages['pp-prefix'], {sepc, QuotePages}), '', '';
    else
    quote_prefix = utilities.substitute (cfg.messages['nopp'], {sepc, QuotePages}), '', '';
    end
    end
                           
    Quote = quote_prefix .. ": " .. Quote;
    else
    Quote = sepc .. " " .. Quote;
    end
     
    PostScript = ""; -- cs1|2 does not supply terminal punctuation when |quote= is set
    end
    -- We check length of PostScript here because it will have been nuked by
    -- the quote parameters. We'd otherwise emit a message even if there wasn't
    -- a displayed postscript.
    -- TODO: Should the max size (1) be configurable?
    -- TODO: Should we check a specific pattern?
    if utilities.is_set(PostScript) and mw.ustring.len(PostScript) > 1 then
    utilities.set_message('maint_postscript')
    end
    local Archived
    if utilities.is_set (ArchiveURL) then
    local arch_text;
    if not utilities.is_set (ArchiveDate) then
    ArchiveDate = utilities.set_message ('err_archive_missing_date');
    end
    if "live" == UrlStatus then
    arch_text = cfg.messages['archived'];
    if sepc ~= "." then arch_text = arch_text:lower() end
    Archived = sepc .. " " .. utilities.substitute ( cfg.messages['archived-live'],
    { external_link( ArchiveURL, arch_text, A:ORIGIN('ArchiveURL'), nil ) .. ArchiveFormat, ArchiveDate } );
    if not utilities.is_set (OriginalURL) then
    Archived = Archived .. " " .. utilities.set_message ('err_archive_missing_url');  
    end
    elseif utilities.is_set (OriginalURL) then -- UrlStatus is empty, 'dead', 'unfit', 'usurped', 'bot: unknown'
    if utilities.in_array (UrlStatus, {'unfit', 'usurped', 'bot: unknown'}) then
    arch_text = cfg.messages['archived-unfit'];
    if sepc ~= "." then arch_text = arch_text:lower() end
    Archived = sepc .. " " .. arch_text .. ArchiveDate; -- format already styled
    if 'bot: unknown' == UrlStatus then
    utilities.set_message ('maint_bot_unknown'); -- and add a category if not already added
    else
    utilities.set_message ('maint_unfit'); -- and add a category if not already added
    end
    else -- UrlStatus is empty, 'dead'
    arch_text = cfg.messages['archived-dead'];
    if sepc ~= "." then arch_text = arch_text:lower() end
    Archived = sepc .. " " .. utilities.substitute ( arch_text,
    { external_link( OriginalURL, cfg.messages['original'], OriginalURL_origin, OriginalAccess ) .. OriginalFormat, ArchiveDate } ); -- format already styled
    end
    else -- OriginalUrl not set
    arch_text = cfg.messages['archived-missing'];
    if sepc ~= "." then arch_text = arch_text:lower() end
    Archived = sepc .. " " .. utilities.substitute ( arch_text,
    { utilities.set_message ('err_archive_missing_url'), ArchiveDate } );
    end
    elseif utilities.is_set (ArchiveFormat) then
    Archived = ArchiveFormat; -- if set and ArchiveURL not set ArchiveFormat has error message
    else
    Archived = ""
    end
    local Lay = '';
    local LaySource = A['LaySource'];
    local LayURL = A['LayURL'];
    local LayFormat = A['LayFormat'];
    LayFormat = style_format (LayFormat, LayURL, 'lay-format', 'lay-url');
    if utilities.is_set (LayURL) then
    if utilities.is_set (LayDate) then LayDate = " (" .. LayDate .. ")" end
    if utilities.is_set (LaySource) then
    LaySource = " &ndash; ''" .. utilities.safe_for_italics (LaySource) .. "''";
    else
    LaySource = "";
    end
    if sepc == '.' then
    Lay = sepc .. " " .. external_link( LayURL, cfg.messages['lay summary'], A:ORIGIN('LayURL'), nil ) .. LayFormat .. LaySource .. LayDate
    else
    Lay = sepc .. " " .. external_link( LayURL, cfg.messages['lay summary']:lower(), A:ORIGIN('LayURL'), nil ) .. LayFormat .. LaySource .. LayDate
    end
    elseif utilities.is_set (LayFormat) then -- Test if |lay-format= is given without giving a |lay-url=
    Lay = sepc .. LayFormat; -- if set and LayURL not set, then LayFormat has error message
    end
     
    local TranscriptURL = A['TranscriptURL']
    local TranscriptFormat = A['TranscriptFormat'];
    TranscriptFormat = style_format (TranscriptFormat, TranscriptURL, 'transcript-format', 'transcripturl');
    local Transcript = A['Transcript'];
    local TranscriptURL_origin = A:ORIGIN('TranscriptURL'); -- get name of parameter that holds TranscriptURL
    if utilities.is_set (Transcript) then
    if utilities.is_set (TranscriptURL) then
    Transcript = external_link( TranscriptURL, Transcript, TranscriptURL_origin, nil );
    end
    Transcript = sepc .. ' ' .. Transcript .. TranscriptFormat;
    elseif utilities.is_set (TranscriptURL) then
    Transcript = external_link( TranscriptURL, nil, TranscriptURL_origin, nil );
    end
     
    local Publisher;
    if utilities.is_set (PublicationDate) then
    PublicationDate = wrap_msg ('published', PublicationDate);
    end
    if utilities.is_set (PublisherName) then
    if utilities.is_set (PublicationPlace) then
    Publisher = sepc .. " " .. PublicationPlace .. ": " .. PublisherName .. PublicationDate;
    else
    Publisher = sepc .. " " .. PublisherName .. PublicationDate; 
    end
    elseif utilities.is_set (PublicationPlace) then
    Publisher= sepc .. " " .. PublicationPlace .. PublicationDate;
    else
    Publisher = PublicationDate;
    end
    local TransPeriodical =  A['TransPeriodical'];
    local TransPeriodical_origin =  A:ORIGIN ('TransPeriodical');
    -- Several of the above rely upon detecting this as nil, so do it last.
    if (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical) or utilities.is_set (TransPeriodical)) then
    if utilities.is_set (Title) or utilities.is_set (TitleNote) then
    Periodical = sepc .. " " .. format_periodical (ScriptPeriodical, ScriptPeriodical_origin, Periodical, TransPeriodical, TransPeriodical_origin);
    else
    Periodical = format_periodical (ScriptPeriodical, ScriptPeriodical_origin, Periodical, TransPeriodical, TransPeriodical_origin);
    end
    end
    local Language = A['Language'];
    if utilities.is_set (Language) then
    Language = language_parameter (Language); -- format, categories, name from ISO639-1, etc.
    else
    Language=''; -- language not specified so make sure this is an empty string;
    --[[ TODO: need to extract the wrap_msg from language_parameter
    so that we can solve parentheses bunching problem with Format/Language/TitleType
    ]]
    end
     
    --[[
    Handle the oddity that is cite speech.  This code overrides whatever may be the value assigned to TitleNote (through |department=) and forces it to be " (Speech)" so that
    the annotation directly follows the |title= parameter value in the citation rather than the |event= parameter value (if provided).
    ]]
    if "speech" == config.CitationClass then -- cite speech only
    TitleNote = " (Speech)"; -- annotate the citation
    if utilities.is_set (Periodical) then -- if Periodical, perhaps because of an included |website= or |journal= parameter
    if utilities.is_set (Conference) then -- and if |event= is set
    Conference = Conference .. sepc .. " "; -- then add appropriate punctuation to the end of the Conference variable before rendering
    end
    end
    end
     
    -- Piece all bits together at last.  Here, all should be non-nil.
    -- We build things this way because it is more efficient in LUA
    -- not to keep reassigning to the same string variable over and over.
     
    local tcommon;
    local tcommon2; -- used for book cite when |contributor= is set
    if utilities.in_array (config.CitationClass, {"journal", "citation"}) and utilities.is_set (Periodical) then
    if utilities.is_set (Others) then Others = safe_join ({Others, sepc .. " "}, sepc) end -- add terminal punctuation & space; check for dup sepc; TODO why do we need to do this here?
    tcommon = safe_join( {Others, Title, TitleNote, Conference, Periodical, Format, TitleType, Series, Language, Edition, Publisher, Agency, Volume}, sepc );
    elseif utilities.in_array (config.CitationClass, {"book", "citation"}) and not utilities.is_set (Periodical) then -- special cases for book cites
    if utilities.is_set (Contributors) then -- when we are citing foreword, preface, introduction, etc.
    tcommon = safe_join( {Title, TitleNote}, sepc ); -- author and other stuff will come after this and before tcommon2
    tcommon2 = safe_join( {Conference, Periodical, Format, TitleType, Series, Language, Volume, Others, Edition, Publisher, Agency}, sepc );
    else
    tcommon = safe_join( {Title, TitleNote, Conference, Periodical, Format, TitleType, Series, Language, Volume, Others, Edition, Publisher, Agency}, sepc );
    end
     
    elseif 'map' == config.CitationClass then -- special cases for cite map
    if utilities.is_set (Chapter) then -- map in a book; TitleType is part of Chapter
    tcommon = safe_join( {Title, Format, Edition, Scale, Series, Language, Cartography, Others, Publisher, Volume}, sepc );
    elseif utilities.is_set (Periodical) then -- map in a periodical
    tcommon = safe_join( {Title, TitleType, Format, Periodical, Scale, Series, Language, Cartography, Others, Publisher, Volume}, sepc );
    else -- a sheet or stand-alone map
    tcommon = safe_join( {Title, TitleType, Format, Edition, Scale, Series, Language, Cartography, Others, Publisher}, sepc );
    end
    elseif 'episode' == config.CitationClass then -- special case for cite episode
    tcommon = safe_join( {Title, TitleNote, TitleType, Series, Language, Edition, Publisher}, sepc );
     
    else -- all other CS1 templates
    tcommon = safe_join( {Title, TitleNote, Conference, Periodical, Format, TitleType, Series, Language,
    Volume, Others, Edition, Publisher, Agency}, sepc );
    end
    if #ID_list > 0 then
    ID_list = safe_join( { sepc .. " ",  table.concat( ID_list, sepc .. " " ), ID }, sepc );
    else
    ID_list = ID;
    end
    local Via = A['Via'];
    Via = utilities.is_set (Via) and  wrap_msg ('via', Via) or '';
    local idcommon;
    if 'audio-visual' == config.CitationClass or 'episode' == config.CitationClass then -- special case for cite AV media & cite episode position transcript
    idcommon = safe_join( { ID_list, URL, Archived, Transcript, AccessDate, Via, Lay, Quote }, sepc );
    else
    idcommon = safe_join( { ID_list, URL, Archived, AccessDate, Via, Lay, Quote }, sepc );
    end
    local text;
    local pgtext = Position .. Sheet .. Sheets .. Page .. Pages .. At;
     
    local OrigDate = A['OrigDate'];
    OrigDate = utilities.is_set (OrigDate) and wrap_msg ('origdate', OrigDate) or '';
    if utilities.is_set (Date) then
    if utilities.is_set (Authors) or utilities.is_set (Editors) then -- date follows authors or editors when authors not set
    Date = " (" .. Date .. ")" .. OrigDate .. sepc .. " "; -- in parentheses
    else -- neither of authors and editors set
    if (string.sub(tcommon, -1, -1) == sepc) then -- if the last character of tcommon is sepc
    Date = " " .. Date .. OrigDate; -- Date does not begin with sepc
    else
    Date = sepc .. " " .. Date .. OrigDate; -- Date begins with sepc
    end
    end
    end
    if utilities.is_set (Authors) then
    if (not utilities.is_set (Date)) then -- when date is set it's in parentheses; no Authors termination
    Authors = terminate_name_list (Authors, sepc); -- when no date, terminate with 0 or 1 sepc and a space
    end
    if utilities.is_set (Editors) then
    local in_text = " ";
    local post_text = "";
    if utilities.is_set (Chapter) and 0 == #c then
    in_text = in_text .. cfg.messages['in'] .. " "
    if (sepc ~= '.') then
    in_text = in_text:lower() -- lowercase for cs2
    end
    end
    if EditorCount <= 1 then
    post_text = " (" .. cfg.messages['editor'] .. ")"; -- be consistent with no-author, no-date case
    else
    post_text = " (" .. cfg.messages['editors'] .. ")";
    end
    Editors = terminate_name_list (in_text .. Editors .. post_text, sepc); -- terminate with 0 or 1 sepc and a space
    end
    if utilities.is_set (Contributors) then -- book cite and we're citing the intro, preface, etc.
    local by_text = sepc .. ' ' .. cfg.messages['by'] .. ' ';
    if (sepc ~= '.') then by_text = by_text:lower() end -- lowercase for cs2
    Authors = by_text .. Authors; -- author follows title so tweak it here
    if utilities.is_set (Editors) and utilities.is_set (Date) then -- when Editors make sure that Authors gets terminated
    Authors = terminate_name_list (Authors, sepc); -- terminate with 0 or 1 sepc and a space
    end
    if (not utilities.is_set (Date)) then -- when date is set it's in parentheses; no Contributors termination
    Contributors = terminate_name_list (Contributors, sepc); -- terminate with 0 or 1 sepc and a space
    end
    text = safe_join( {Contributors, Date, Chapter, tcommon, Authors, Place, Editors, tcommon2, pgtext, idcommon }, sepc );
    else
    text = safe_join( {Authors, Date, Chapter, Place, Editors, tcommon, pgtext, idcommon }, sepc );
    end
    elseif utilities.is_set (Editors) then
    if utilities.is_set (Date) then
    if EditorCount <= 1 then
    Editors = Editors .. ", " .. cfg.messages['editor'];
    else
    Editors = Editors .. ", " .. cfg.messages['editors'];
    end
    else
    if EditorCount <= 1 then
    Editors = Editors .. " (" .. cfg.messages['editor'] .. ")" .. sepc .. " "
    else
    Editors = Editors .. " (" .. cfg.messages['editors'] .. ")" .. sepc .. " "
    end
    end
    text = safe_join( {Editors, Date, Chapter, Place, tcommon, pgtext, idcommon}, sepc );
    else
    if utilities.in_array (config.CitationClass, {"journal", "citation"}) and utilities.is_set (Periodical) then
    text = safe_join( {Chapter, Place, tcommon, pgtext, Date, idcommon}, sepc );
    else
    text = safe_join( {Chapter, Place, tcommon, Date, pgtext, idcommon}, sepc );
    end
    end
    if utilities.is_set (PostScript) and PostScript ~= sepc then
    text = safe_join( {text, sepc}, sepc ); -- Deals with italics, spaces, etc.
    text = text:sub(1, -sepc:len() - 1);
    end
    text = safe_join( {text, PostScript}, sepc );
     
    -- Now enclose the whole thing in a <cite> element
    local options = {};
    if utilities.is_set (config.CitationClass) and config.CitationClass ~= "citation" then
    options.class = string.format ('%s %s %s', 'citation', config.CitationClass, utilities.is_set (Mode) and Mode or 'cs1'); -- class=citation required for blue highlight when used with |ref=
    else
    options.class = string.format ('%s %s', 'citation', utilities.is_set (Mode) and Mode or 'cs2');
    end
     
    local Ref = A['Ref'];
    if 'harv' == Ref then -- need to check this before setting to default
    utilities.set_message ('maint_ref_harv'); -- add maint cat to identify templates that have this now-extraneous param value
    elseif not utilities.is_set (Ref) then
    Ref = 'harv'; -- set as default when not set externally
    end
    if 'none' ~= cfg.keywords_xlate[Ref:lower()] then
    local id = Ref
    local namelist = {}; -- holds selected contributor, author, editor name list
    local year = first_set ({Year, anchor_year}, 2); -- Year first for legacy citations and for YMD dates that require disambiguation
     
    if #c > 0 then -- if there is a contributor list
    namelist = c; -- select it
    elseif #a > 0 then -- or an author list
    namelist = a;
    elseif #e > 0 then -- or an editor list
    namelist = e;
    end
    local citeref_id
    if #namelist > 0 then -- if there are names in namelist
    citeref_id = make_citeref_id (namelist, year); -- go make the CITEREF anchor
    else
    citeref_id = ''; -- unset
    end
    if citeref_id == Ref then
    utilities.set_message ('maint_ref_duplicates_default');
    end
    if 'harv' == Ref then
    id = citeref_id
    end
    options.id = id;
    end
    if string.len(text:gsub("<span[^>/]*>(.-)</span>", "%1"):gsub("%b<>", "")) <= 2 then -- remove <span> tags and other HTML-like markup; then get length of what remains
    z.error_categories = {};
    text = utilities.set_message ('err_empty_citation');
    z.message_tail = {};
    end
    local render = {}; -- here we collect the final bits for concatenation into the rendered citation
     
    if utilities.is_set (options.id) then -- here we wrap the rendered citation in <cite ...>...</cite> tags
    table.insert (render, utilities.substitute (cfg.presentation['cite-id'], {mw.uri.anchorEncode(options.id), mw.text.nowiki(options.class), text})); -- when |ref= is set
    else
    table.insert (render, utilities.substitute (cfg.presentation['cite'], {mw.text.nowiki(options.class), text})); -- all other cases
    end
     
    table.insert (render, utilities.substitute (cfg.presentation['ocins'], {OCinSoutput})); -- append metadata to the citation
     
    if 0 ~= #z.message_tail then
    table.insert (render, ' ');
    for i,v in ipairs( z.message_tail ) do
    if utilities.is_set (v[1]) then
    if i == #z.message_tail then
    table.insert (render, utilities.error_comment ( v[1], v[2] ));
    else
    table.insert (render, utilities.error_comment ( v[1] .. "; ", v[2] ));
    end
    end
    end
    end
     
    if 0 ~= #z.maintenance_cats then
    local maint_msgs = {}; -- here we collect all of the maint messages
    for _, v in ipairs( z.maintenance_cats ) do -- append maintenance categories
    local maint = {}; -- here we assemble a maintenence message
    table.insert (maint, v); -- maint msg is the category name
    table.insert (maint, ' ('); -- open the link text
    table.insert (maint, utilities.substitute (cfg.messages[':cat wikilink'], {v})); -- add the link
    table.insert (maint, ')'); -- and close it
    table.insert (maint_msgs, table.concat (maint)); -- assemble new maint message and add it to the maint_msgs table
    end
    table.insert (render, utilities.substitute (cfg.presentation['hidden-maint'], table.concat (maint_msgs, ' '))); -- wrap the group of maint message with proper presentation and save
    end
    if not no_tracking_cats then
    for _, v in ipairs( z.error_categories ) do -- append error categories
    table.insert (render, utilities.substitute (cfg.messages['cat wikilink'], {v}));
    end
    for _, v in ipairs( z.maintenance_cats ) do -- append maintenance categories
    table.insert (render, utilities.substitute (cfg.messages['cat wikilink'], {v}));
    end
    for _, v in ipairs( z.properties_cats ) do -- append properties categories
    table.insert (render, utilities.substitute (cfg.messages['cat wikilink'], {v}));
    end
    end
     
    return table.concat (render);
    end
     
     
    --[[--------------------------< V A L I D A T E >--------------------------------------------------------------
     
    Looks for a parameter's name in one of several whitelists.
     
    Parameters in the whitelist can have three values:
    true - active, supported parameters
    false - deprecated, supported parameters
    nil - unsupported parameters
    ]]
     
    local function validate (name, cite_class, empty)
    local name = tostring (name);
    local enum_name; -- for enumerated parameters, is name with enumerator replaced with '#'
    local state;
    local function state_test (state, name) -- local function to do testing of state values
    if true == state then return true; end -- valid actively supported parameter
    if false == state then
    if empty then return nil; end -- empty deprecated parameters are treated as unknowns
    deprecated_parameter (name); -- parameter is deprecated but still supported
    return true;
    end
    if 'discouraged' == state then
    discouraged_parameter (name); -- parameter is discouraged but still supported
    return true;
    end
    return nil;
    end
     
    if name:find ('#') then -- # is a cs1|2 reserved character so parameters with # not permitted
    return nil;
    end
     
    if utilities.in_array (cite_class, whitelist.preprint_template_list ) then -- limited parameter sets allowed for these templates
    state = whitelist.limited_basic_arguments[name];
    if true == state_test (state, name) then return true; end
     
    state = whitelist.preprint_arguments[cite_class][name]; -- look in the parameter-list for the template identified by cite_class
    if true == state_test (state, name) then return true; end
     
    -- limited enumerated parameters list
    enum_name = name:gsub("%d+", "#" ); -- replace digit(s) with # (last25 becomes last#) (mw.ustring because non-Western 'local' digits)
    state = whitelist.limited_numbered_arguments[enum_name];
    if true == state_test (state, name) then return true; end
     
    return false; -- not supported because not found or name is set to nil
    end -- end limited parameter-set templates
     
    if utilities.in_array (cite_class, whitelist.unique_param_template_list) then -- experiment for template-specific parameters for templates that accept parameters from the basic argument list
    state = whitelist.unique_arguments[cite_class][name]; -- look in the template-specific parameter-lists for the template identified by cite_class
    if true == state_test (state, name) then return true; end
    end -- if here, fall into general validation
    state = whitelist.basic_arguments[name]; -- all other templates; all normal parameters allowed
    if true == state_test (state, name) then return true; end
     
    -- all enumerated parameters allowed
    enum_name = name:gsub("%d+", "#" ); -- replace digit(s) with # (last25 becomes last#) (mw.ustring because non-Western 'local' digits)
    state = whitelist.numbered_arguments[enum_name];
    if true == state_test (state, name) then return true; end
     
    return false; -- not supported because not found or name is set to nil
    end
    end


    -- This is used by template {{efn}}.
     
    function z.efn(frame)
    --[=[-------------------------< I N T E R _ W I K I _ C H E C K >----------------------------------------------
        local pframe = frame:getParent()
     
        local config = frame.args -- the arguments passed BY the template, in the wikitext of the template itself
    check <value> for inter-language interwiki-link markup. <prefix> must be a MediaWiki-recognized language
        local args = pframe.args -- the arguments passed TO the template, in the wikitext that instantiates the template
    code. when these values have the form (without leading colon):
        return z.mw.text.tag({name="ref",contents=(args[1] or ""),params={name=args.name,group=config.default_group}}, frame)
    [[<prefix>:link|label]] return label as plain-text
    [[<prefix>:link]] return <prefix>:link as plain-text
     
    return value as is else
     
    ]=]
     
    local function inter_wiki_check (parameter, value)
    local prefix = value:match ('%[%[(%a+):'); -- get an interwiki prefix if one exists
    local _;
    if prefix and cfg.inter_wiki_map[prefix:lower()] then -- if prefix is in the map, needs preceding colon so
    table.insert( z.message_tail, {utilities.set_message ('err_bad_paramlink', parameter)}); -- emit an error message
    _, value, _ = utilities.is_wikilink (value); -- extract label portion from wikilink
    end
    return value;
    end
    end


    return z
     
    ---------------------------------------------------------------------
    --[[--------------------------< M I S S I N G _ P I P E _ C H E C K >------------------------------------------
    --NOTES
     
    --
    Look at the contents of a parameter. If the content has a string of characters and digits followed by an equal
    -- NOTE A1: This Lua module was originally designed to handle a mix
    sign, compare the alphanumeric string to the list of cs1|2 parameters. If found, then the string is possibly a
    --      of citation styles, crossing Vancouver style with Wikipedia's
    parameter that is missing its pipe. There are two tests made:
    --      local Citation Style 1 (CS1) from {Template:Citation/core}.
    {{cite ... |title=Title access-date=2016-03-17}} -- the first parameter has a value and whitespace separates that value from the missing pipe parameter name
    --      However, the conflicting positions of parameters, scattered
    {{cite ... |title=access-date=2016-03-17}} -- the first parameter has no value (whitespace after the first = is trimmed by MediaWiki)
    --      in twisted locations across this module, led to a separate
    cs1|2 shares some parameter names with XML/HTML attributes: class=, title=, etc.  To prevent false positives XML/HTML
    --      variation just to untangle the CS1 format of citations.
    tags are removed before the search.
    --
     
    -- NOTE D2: The placement of dots and other separators between the
    If a missing pipe is detected, this function adds the missing pipe maintenance category.
    --     displayed parameters has been a continual headache, to keep
     
    --     coordinated with the data in parentheses "(data)". There
    ]]
    --      has been a need to pre-check for the existence of related
     
    --      options, to keep from putting double-dots ".." in some cases.
    local function missing_pipe_check (parameter, value)
    --      In particular, the omission of the "title=" parameter has led
    local capture;
    --     to several cases of a spurious dot ". ." because the original
    value = value:gsub ('%b<>', ''); -- remove XML/HTML tags because attributes: class=, title=, etc.
    --      design had treated the title as a mandatory parameter.
     
    --
    capture = value:match ('%s+(%a[%w%-]+)%s*=') or value:match ('^(%a[%w%-]+)%s*='); -- find and categorize parameters with possible missing pipes
    ------------------------------------------------------------------------
    if capture and validate (capture) then -- if the capture is a valid parameter name
    --HISTORY:
    table.insert( z.message_tail, {utilities.set_message ('err_missing_pipe', parameter)});
    --18Oct2012 Fixed lead-space in Chapter by omitting " ".
    end
    --18Oct2012 Fixed lead-space in Chapter/Title as end " " of Authors/Date/...
    end
    --19Oct2012 Put HISTORY comments to log major changes (not typos).
     
    --19Oct2012 Fixed extra dot ".." in Title by omitting at end of "tcommon=...".
     
    --19Oct2012 For pages, put &nbsp in "p.&nbsp;" etc.
    --[[--------------------------< H A S _ E X T R A N E O U S _ P U N C T >--------------------------------------
    --19Oct2012 Enhanced "pages=" to detect lone page as "p." else "pp." prefix.
     
    --19Oct2012 Fixed to show "." after Periodical name (work, newspaper...).
    look for extraneous terminal punctuation in most parameter values; parameters listed in skip table are not checked
    --19Oct2012 Fixed web-link to have spaces "[...  Archived] from the original".
     
    --19Oct2012 Fixed to show ";" between authors & coauthors.
    ]]
    --19Oct2012 Fixed to omit extra "." after coauthors.
     
    --20Oct2012 Fixed COinS data to not urlencode all, as "ctx_ver=Z39.88-2004"
    local function has_extraneous_punc (param, value)
    --20Oct2012 Fixed COinS to not end as "&" but use lead "&rft...=" form.
    if 'number' == type (param) then
    --20Oct2012 Fixed COinS to not url.encode page's "rfr_id=..." pagename.
    return;
    --20Oct2012 Fixed COinS data when "web" to default to rft.genre "book".
    end
    --05Nov2012 Add a span wrapper even when there is no Ref parameter
    --15Feb2013 Added Agency for "agency=xx".
    param = param:gsub ('%d+', '#'); -- enumerated name-list mask params allow terminal punct; normalize
    --19Feb2013 Put NOTES comments to explain module operation.
    if cfg.punct_skip[param] then
    --19Feb2013 Copied as Module:Citation/CS1 to alter to match wp:CS1 form.
    return; -- parameter name found in the skip table so done
    --19Feb2013 Changed OrigYear to use [__] for CS1 style.
    end
    --19Feb2013 Fixed to not show duplicate Publisher/Agency.
    --19Feb2013 Moved page-number parameters to after final date.
    if value:match ('[,;:]$') then
    --19Feb2013 Fixed to not put double-dots after title again.
    utilities.set_message ('maint_extra_punct'); -- has extraneous punctuation; add maint cat
    --20Feb2013 Changed to omit dot "." if already ends with dot.
    end
    --20Feb2013 If class "journal" shows Publisher after Periodical/Series.
    end
    --20Feb2013 Shifted Format to after Language, and Others after Volume.
     
    --20Feb2013 Set AccessDate + <span class="reference-accessdate">
     
    --20Feb2013 Fixed url when deadurl=no.
    --[[--------------------------< C I T A T I O N >--------------------------------------------------------------
    --20Feb2013 Added sepc for separator character between parameters.
     
    --20Feb2013 Put "OCLC" for "Online Computer Library Center".
    This is used by templates such as {{cite book}} to create the actual citation text.
    --20Feb2013 Fix empty "authorlink=" as person.link ~= "".
     
    --20Feb2013 Added space after AuthorSep & AuthorNameSep.
    ]]
    --21Feb2013 Added args.contributor (was missing parameter).
     
    --21Feb2013 Fixed EditorSep (was misspelled "EdithorSep").
    local function citation(frame)
    --21Feb2013 Set OCinSdata.rft_val_fmt = "info:ofi/fmt:kev:mtx:book"
    Frame = frame; -- save a copy in case we need to display an error message in preview mode
    --21Feb2013 Checked to omit blank codes (asin= | doi= etc.).
    local pframe = frame:getParent()
    --21Feb2013 Set enddot to end line if not config.CitationClass "citation".
    local styles;
    --21Feb2013 Fixed to show "issn=x" as the ISSN code.
    --21Feb2013 Fixed to show "id=x" after Zbl code.
    if nil ~= string.find (frame:getTitle(), 'sandbox', 1, true) then -- did the {{#invoke:}} use sandbox version?
    --21Feb2013 Changed to omit double-dot before date when already dot.
    cfg = mw.loadData ('Module:Citation/CS1/Configuration/sandbox'); -- load sandbox versions of support modules
    --21Feb2013 Order config.CitationClass "citation": Volume, Issue, Publisher.
    whitelist = mw.loadData ('Module:Citation/CS1/Whitelist/sandbox');
    --21Feb2013 Put warning "Bad DOI (expected "10."..)" in DOI result.
    utilities = require ('Module:Citation/CS1/Utilities/sandbox');
    --21Feb2013 Automatically unbolded volume+comma when > 4 long.
    validation = require ('Module:Citation/CS1/Date_validation/sandbox');
    --21Feb2013 Changed to allow lowercase "asin-tld".
    identifiers = require ('Module:Citation/CS1/Identifiers/sandbox');
    --22Feb2013 Fixed ref=harv to extract Year from Date.
    metadata = require ('Module:Citation/CS1/COinS/sandbox');
    --22Feb2013 Set Harvard refer. span id if config.CitationClass "citation".
    styles = 'Module:Citation/CS1/sandbox/styles.css';
    --22Feb2013 Fixed config.CitationClass "citation" as span class="citation".
    --22Feb2013 Capitalized "Archived/Retrieved" only when sepc is dot ".".
    else -- otherwise
    --23Feb2013 Fixed author editor for "in" or "In" and put space after sepc.
    cfg = mw.loadData ('Module:Citation/CS1/Configuration'); -- load live versions of support modules
    --23Feb2013 Changed to omit dot in "et al." when sepc is "." separator.
    whitelist = mw.loadData ('Module:Citation/CS1/Whitelist');
    --23Feb2013 Fixed "author1-first" to also get args.given or args.given1.
    utilities = require ('Module:Citation/CS1/Utilities');
    --23Feb2013 Fixed args.article to set Title, after Periodical is Title.
    validation = require ('Module:Citation/CS1/Date_validation');
    --23Feb2013 Fixed to allow blank Title (such as "contribution=mytitle").
    identifiers = require ('Module:Citation/CS1/Identifiers');
    --23Feb2013 Fixed double-dot ".." at end of Editors list
    metadata = require ('Module:Citation/CS1/COinS');
    --26Feb2013 Moved "issue=" data to show before "page=".
    styles = 'Module:Citation/CS1/styles.css';
    --26Feb2013 Moved "type=" data to show after "format=".
    end
    --26Feb2013 For "pmc=" link, omitted suffix "/?tool=pmcentrez".
     
    --27Feb2013 For coauthors, omitted extra separator after authors.
    utilities.set_selected_modules (cfg); -- so that functions in Utilities can see the selected cfg tables
    --27Feb2013 For date, allowed empty date to use month/day/year.
    identifiers.set_selected_modules (cfg, utilities); -- so that functions in Identifiers can see the selected cfg tables and selected Utilities module
    --27Feb2013 Fixed double-dot ".." at end of authors/coauthors list.
    validation.set_selected_modules (cfg, utilities); -- so that functions in Date validataion can see selected cfg tables and the selected Utilities module
    --27Feb2013 Reset editor suffix as ", ed." when date exists.
    metadata.set_selected_modules (cfg, utilities); -- so that functions in COinS can see the selected cfg tables and selected Utilities module
    --27Feb2013 Removed duplicate display of "others=" data.
     
    --27Feb2013 Removed parentheses "( )" around "department" TitleNote.
    z = utilities.z; -- table of error and category tables in Module:Citation/CS1/Utilities
    --05Mar2013 Moved Language to follow Periodical or Series.
     
    --05Mar2013 Fixed Edition to follow Series or Volume.
    local args = {}; -- table where we store all of the template's arguments
    --05Mar2013 Fixed class encyclopaedia to show article as quoted Chapter.
    local suggestions = {}; -- table where we store suggestions if we need to loadData them
    --05Mar2013 Fixed class encyclopaedia to show page as "pp." or "p.".
    local error_text, error_state;
    --07Mar2013 Changed class encyclopaedia to omit "( )" around publisher.
     
    --07Mar2013 Fixed end double-dot by string.sub(idcommon,-1,-1) was "-1,1".
    local config = {}; -- table to store parameters from the module {{#invoke:}}
    --13Mar2013 Removed enddot "." after "quote=" parameter.
    for k, v in pairs( frame.args ) do -- get parameters from the {{#invoke}} frame
    --13Mar2013 Changed config.CitationClass "news" to use "p." page format.
    config[k] = v;
    --13Mar2013 Fixed missing "location=" when "web" or "encyclopaedia".
    -- args[k] = v; -- crude debug support that allows us to render a citation from module {{#invoke:}}; skips parameter validation; TODO: keep?
    --14Mar2013 Fixed end double-dot after book/work title.
    end
    --14Mar2013 Fixed double-dot before "p." or "pp." page number.
     
    --14Mar2013 Fixed config.CitationClass "book" to use p./pp. page.
    local capture; -- the single supported capture when matching unknown parameters using patterns
    --
    local empty_unknowns = {}; -- sequence table to hold empty unknown params for error message listing
    --End
    for k, v in pairs( pframe.args ) do -- get parameters from the parent (template) frame
    v = mw.ustring.gsub (v, '^%s*(.-)%s*$', '%1'); -- trim leading/trailing whitespace; when v is only whitespace, becomes empty string
    if v ~= '' then
    if ('string' == type (k)) then
    k = mw.ustring.gsub (k, '%d', cfg.date_names.local_digits); -- for enumerated parameters, translate 'local' digits to Western 0-9
    end
    if not validate( k, config.CitationClass ) then
    error_text = "";
    if type( k ) ~= 'string' then
    -- exclude empty numbered parameters
    if v:match("%S+") ~= nil then
    error_text, error_state = utilities.set_message ( 'err_text_ignored', {v}, true );
    end
    elseif validate( k:lower(), config.CitationClass ) then
    error_text, error_state = utilities.set_message ( 'err_parameter_ignored_suggest', {k, k:lower()}, true ); -- suggest the lowercase version of the parameter
    else
    if nil == suggestions.suggestions then -- if this table is nil then we need to load it
    if nil ~= string.find (frame:getTitle(), 'sandbox', 1, true) then -- did the {{#invoke:}} use sandbox version?
    suggestions = mw.loadData( 'Module:Citation/CS1/Suggestions/sandbox' ); -- use the sandbox version
    else
    suggestions = mw.loadData( 'Module:Citation/CS1/Suggestions' ); -- use the live version
    end
    end
    for pattern, param in pairs (suggestions.patterns) do -- loop through the patterns to see if we can suggest a proper parameter
    capture = k:match (pattern); -- the whole match if no capture in pattern else the capture if a match
    if capture then -- if the pattern matches
    param = utilities.substitute (param, capture); -- add the capture to the suggested parameter (typically the enumerator)
    if validate (param, config.CitationClass) then -- validate the suggestion to make sure that the suggestion is supported by this template (necessary for limited parameter lists)
    error_text, error_state = utilities.set_message ('err_parameter_ignored_suggest', {k, param}, true); -- set the suggestion error message
    else
    error_text, error_state = utilities.set_message ( 'err_parameter_ignored', {k}, true ); -- suggested param not supported by this template
    v = ''; -- unset
    end
    end
    end
    if not utilities.is_set (error_text) then -- couldn't match with a pattern, is there an explicit suggestion?
    if (suggestions.suggestions[ k:lower() ] ~= nil) and validate (suggestions.suggestions[ k:lower() ], config.CitationClass) then
    error_text, error_state = utilities.set_message ( 'err_parameter_ignored_suggest', {k, suggestions.suggestions[ k:lower() ]}, true );
    else
    error_text, error_state = utilities.set_message ( 'err_parameter_ignored', {k}, true );
    v = ''; -- unset value assigned to unrecognized parameters (this for the limited parameter lists)
    end
    end
    end  
    if error_text ~= '' then
    table.insert( z.message_tail, {error_text, error_state} );
    end
    end
     
    args[k] = v; -- save this parameter and its value
     
    elseif not utilities.is_set (v) then -- for empty parameters
    if not validate (k, config.CitationClass, true) then -- is this empty parameter a valid parameter
    k = ('' == k) and '(empty string)' or k; -- when k is empty string (or was space(s) trimmed to empty string), replace with descriptive text
    table.insert (empty_unknowns, utilities.wrap_style ('parameter', k)); -- format for error message and add to the list
    end
    -- crude debug support that allows us to render a citation from module {{#invoke:}} TODO: keep?
    -- elseif args[k] ~= nil or (k == 'postscript') then -- when args[k] has a value from {{#invoke}} frame (we don't normally do that)
    -- args[k] = v; -- overwrite args[k] with empty string from pframe.args[k] (template frame); v is empty string here
    end -- not sure about the postscript bit; that gets handled in parameter validation; historical artifact?
    end
     
    if 0 ~= #empty_unknowns then -- create empty unknown error message
    table.insert (z.message_tail, {utilities.set_message ('err_param_unknown_empty', {
    1 == #empty_unknowns and '' or 's',
    utilities.make_sep_list (#empty_unknowns, empty_unknowns)
    }, true )});
    end
     
    for k, v in pairs( args ) do
    if 'string' == type (k) then -- don't evaluate positional parameters
    has_invisible_chars (k, v); -- look for invisible characters
    end
    has_extraneous_punc (k, v); -- look for extraneous terminal punctuation in parameter values
    missing_pipe_check (k, v); -- do we think that there is a parameter that is missing a pipe?
    args[k] = inter_wiki_check (k, v); -- when language interwiki-linked parameter missing leading colon replace with wiki-link label
    end
     
    return table.concat ({
    frame:extensionTag ('templatestyles', '', {src=styles}),
    citation0( config, args)
    });
    end
     
    --[[--------------------------< E X P O R T E D  F U N C T I O N S >------------------------------------------
    ]]
     
    return {citation = citation};

    Latest revision as of 11:41, 21 May 2021

    Documentation for this module may be created at Module:Citation/CS1/doc

    
    require('Module:No globals');
    
    --[[--------------------------< F O R W A R D   D E C L A R A T I O N S >--------------------------------------
    each of these counts against the Lua upvalue limit
    ]]
    
    local validation;																-- functions in Module:Citation/CS1/Date_validation
    
    local utilities;																-- functions in Module:Citation/CS1/Utilities
    local z ={};																	-- table of tables in Module:Citation/CS1/Utilities
    
    local identifiers;																-- functions and tables in Module:Citation/CS1/Identifiers
    local metadata;																	-- functions in Module:Citation/CS1/COinS
    local cfg = {};																	-- table of configuration tables that are defined in Module:Citation/CS1/Configuration
    local whitelist = {};															-- table of tables listing valid template parameter names; defined in Module:Citation/CS1/Whitelist
    
    --[[------------------< P A G E   S C O P E   V A R I A B L E S >---------------
    declare variables here that have page-wide scope that are not brought in from
    other modules; that are created here and used here
    ]]
    local added_deprecated_cat;														-- Boolean flag so that the category is added only once
    local added_discouraged_cat;													-- Boolean flag so that the category is added only once
    local added_vanc_errs;															-- Boolean flag so we only emit one Vancouver error / category
    local Frame;																	-- holds the module's frame table
    
    --[[--------------------------< F I R S T _ S E T >------------------------------------------------------------
    
    Locates and returns the first set value in a table of values where the order established in the table,
    left-to-right (or top-to-bottom), is the order in which the values are evaluated.  Returns nil if none are set.
    
    This version replaces the original 'for _, val in pairs do' and a similar version that used ipairs.  With the pairs
    version the order of evaluation could not be guaranteed.  With the ipairs version, a nil value would terminate
    the for-loop before it reached the actual end of the list.
    
    ]]
    
    local function first_set (list, count)
    	local i = 1;
    	while i <= count do															-- loop through all items in list
    		if utilities.is_set( list[i] ) then
    			return list[i];														-- return the first set list member
    		end
    		i = i + 1;																-- point to next
    	end
    end
    
    
    --[[--------------------------< A D D _ V A N C _ E R R O R >----------------------------------------------------
    
    Adds a single Vancouver system error message to the template's output regardless of how many error actually exist.
    To prevent duplication, added_vanc_errs is nil until an error message is emitted.
    
    added_vanc_errs is a Boolean declared in page scope variables above
    
    ]]
    
    local function add_vanc_error (source, position)
    	if added_vanc_errs then return end
    		
    	added_vanc_errs = true;														-- note that we've added this category
    	table.insert( z.message_tail, { utilities.set_message ( 'err_vancouver', {source, position}, true ) } );
    end
    
    
    --[[--------------------------< I S _ S C H E M E >------------------------------------------------------------
    
    does this thing that purports to be a URI scheme seem to be a valid scheme?  The scheme is checked to see if it
    is in agreement with http://tools.ietf.org/html/std66#section-3.1 which says:
    	Scheme names consist of a sequence of characters beginning with a
       letter and followed by any combination of letters, digits, plus
       ("+"), period ("."), or hyphen ("-").
    
    returns true if it does, else false
    
    ]]
    
    local function is_scheme (scheme)
    	return scheme and scheme:match ('^%a[%a%d%+%.%-]*:');						-- true if scheme is set and matches the pattern
    end
    
    
    --[=[-------------------------< I S _ D O M A I N _ N A M E >--------------------------------------------------
    
    Does this thing that purports to be a domain name seem to be a valid domain name?
    
    Syntax defined here: http://tools.ietf.org/html/rfc1034#section-3.5
    BNF defined here: https://tools.ietf.org/html/rfc4234
    Single character names are generally reserved; see https://tools.ietf.org/html/draft-ietf-dnsind-iana-dns-01#page-15;
    	see also [[Single-letter second-level domain]]
    list of TLDs: https://www.iana.org/domains/root/db
    
    RFC 952 (modified by RFC 1123) requires the first and last character of a hostname to be a letter or a digit.  Between
    the first and last characters the name may use letters, digits, and the hyphen.
    
    Also allowed are IPv4 addresses. IPv6 not supported
    
    domain is expected to be stripped of any path so that the last character in the last character of the TLD.  tld
    is two or more alpha characters.  Any preceding '//' (from splitting a URL with a scheme) will be stripped
    here.  Perhaps not necessary but retained in case it is necessary for IPv4 dot decimal.
    
    There are several tests:
    	the first character of the whole domain name including subdomains must be a letter or a digit
    	internationalized domain name (ASCII characters with .xn-- ASCII Compatible Encoding (ACE) prefix xn-- in the TLD) see https://tools.ietf.org/html/rfc3490
    	single-letter/digit second-level domains in the .org, .cash, and .today TLDs
    	q, x, and z SL domains in the .com TLD
    	i and q SL domains in the .net TLD
    	single-letter SL domains in the ccTLDs (where the ccTLD is two letters)
    	two-character SL domains in gTLDs (where the gTLD is two or more letters)
    	three-plus-character SL domains in gTLDs (where the gTLD is two or more letters)
    	IPv4 dot-decimal address format; TLD not allowed
    
    returns true if domain appears to be a proper name and TLD or IPv4 address, else false
    
    ]=]
    
    local function is_domain_name (domain)
    	if not domain then
    		return false;															-- if not set, abandon
    	end
    	
    	domain = domain:gsub ('^//', '');											-- strip '//' from domain name if present; done here so we only have to do it once
    	
    	if not domain:match ('^[%w]') then											-- first character must be letter or digit
    		return false;
    	end
    
    	if domain:match ('^%a+:') then												-- hack to detect things that look like s:Page:Title where Page: is namespace at Wikisource
    		return false;
    	end
    
    	local patterns = {															-- patterns that look like URLs
    		'%f[%w][%w][%w%-]+[%w]%.%a%a+$',										-- three or more character hostname.hostname or hostname.tld
    		'%f[%w][%w][%w%-]+[%w]%.xn%-%-[%w]+$',									-- internationalized domain name with ACE prefix
    		'%f[%a][qxz]%.com$',													-- assigned one character .com hostname (x.com times out 2015-12-10)
    		'%f[%a][iq]%.net$',														-- assigned one character .net hostname (q.net registered but not active 2015-12-10)
    		'%f[%w][%w]%.%a%a$',													-- one character hostname and ccTLD (2 chars)
    		'%f[%w][%w][%w]%.%a%a+$',												-- two character hostname and TLD
    		'^%d%d?%d?%.%d%d?%d?%.%d%d?%d?%.%d%d?%d?',								-- IPv4 address
    		}
    
    	for _, pattern in ipairs (patterns) do										-- loop through the patterns list
    		if domain:match (pattern) then
    			return true;														-- if a match then we think that this thing that purports to be a URL is a URL
    		end
    	end
    
    	for _, d in ipairs ({'cash', 'company', 'today', 'org'}) do					-- look for single letter second level domain names for these top level domains
    		if domain:match ('%f[%w][%w]%.' .. d) then
    			return true
    		end
    	end
    	return false;																-- no matches, we don't know what this thing is
    end
    
    
    --[[--------------------------< I S _ U R L >------------------------------------------------------------------
    
    returns true if the scheme and domain parts of a URL appear to be a valid URL; else false.
    
    This function is the last step in the validation process.  This function is separate because there are cases that
    are not covered by split_url(), for example is_parameter_ext_wikilink() which is looking for bracketted external
    wikilinks.
    
    ]]
    
    local function is_url (scheme, domain)
    	if utilities.is_set (scheme) then											-- if scheme is set check it and domain
    		return is_scheme (scheme) and is_domain_name (domain);
    	else
    		return is_domain_name (domain);											-- scheme not set when URL is protocol-relative
    	end
    end
    
    
    --[[--------------------------< S P L I T _ U R L >------------------------------------------------------------
    
    Split a URL into a scheme, authority indicator, and domain.
    
    First remove Fully Qualified Domain Name terminator (a dot following TLD) (if any) and any path(/), query(?) or fragment(#).
    
    If protocol-relative URL, return nil scheme and domain else return nil for both scheme and domain.
    
    When not protocol-relative, get scheme, authority indicator, and domain.  If there is an authority indicator (one
    or more '/' characters immediately following the scheme's colon), make sure that there are only 2.
    
    Any URL that does not have news: scheme must have authority indicator (//).  TODO: are there other common schemes
    like news: that don't use authority indicator?
    
    Strip off any port and path;
    
    ]]
    
    local function split_url (url_str)
    	local scheme, authority, domain;
    	
    	url_str = url_str:gsub ('([%a%d])%.?[/%?#].*$', '%1');						-- strip FQDN terminator and path(/), query(?), fragment (#) (the capture prevents false replacement of '//')
    
    	if url_str:match ('^//%S*') then											-- if there is what appears to be a protocol-relative URL
    		domain = url_str:match ('^//(%S*)')
    	elseif url_str:match ('%S-:/*%S+') then										-- if there is what appears to be a scheme, optional authority indicator, and domain name
    		scheme, authority, domain = url_str:match ('(%S-:)(/*)(%S+)');			-- extract the scheme, authority indicator, and domain portions
    		if utilities.is_set (authority) then
    			authority = authority:gsub ('//', '', 1);							-- replace place 1 pair of '/' with nothing;
    			if utilities.is_set(authority) then									-- if anything left (1 or 3+ '/' where authority should be) then
    				return scheme;													-- return scheme only making domain nil which will cause an error message
    			end
    		else
    			if not scheme:match ('^news:') then									-- except for news:..., MediaWiki won't link URLs that do not have authority indicator; TODO: a better way to do this test?
    				return scheme;													-- return scheme only making domain nil which will cause an error message
    			end
    		end
    		domain = domain:gsub ('(%a):%d+', '%1');								-- strip port number if present
    	end
    	
    	return scheme, domain;
    end
    
    
    --[[--------------------------< L I N K _ P A R A M _ O K >---------------------------------------------------
    
    checks the content of |title-link=, |series-link=, |author-link=, etc. for properly formatted content: no wikilinks, no URLs
    
    Link parameters are to hold the title of a Wikipedia article, so none of the WP:TITLESPECIALCHARACTERS are allowed:
    	# < > [ ] | { } _
    except the underscore which is used as a space in wiki URLs and # which is used for section links
    
    returns false when the value contains any of these characters.
    
    When there are no illegal characters, this function returns TRUE if value DOES NOT appear to be a valid URL (the
    |<param>-link= parameter is ok); else false when value appears to be a valid URL (the |<param>-link= parameter is NOT ok).
    
    ]]
    
    local function link_param_ok (value)
    	local scheme, domain;
    	if value:find ('[<>%[%]|{}]') then											-- if any prohibited characters
    		return false;
    	end
    
    	scheme, domain = split_url (value);											-- get scheme or nil and domain or nil from URL; 
    	return not is_url (scheme, domain);											-- return true if value DOES NOT appear to be a valid URL
    end
    
    
    --[[--------------------------< L I N K _ T I T L E _ O K >---------------------------------------------------
    
    Use link_param_ok() to validate |<param>-link= value and its matching |<title>= value.
    
    |<title>= may be wiki-linked but not when |<param>-link= has a value.  This function emits an error message when
    that condition exists
    
    check <link> for inter-language interwiki-link prefix.  prefix must be a MediaWiki-recognized language
    code and must begin with a colon.
    
    ]]
    
    local function link_title_ok (link, lorig, title, torig)
    local orig;
    	if utilities.is_set (link) then 											-- don't bother if <param>-link doesn't have a value
    		if not link_param_ok (link) then										-- check |<param>-link= markup
    			orig = lorig;														-- identify the failing link parameter
    		elseif title:find ('%[%[') then											-- check |title= for wikilink markup
    			orig = torig;														-- identify the failing |title= parameter
    		elseif link:match ('^%a+:') then										-- if the link is what looks like an interwiki
    			local prefix = link:match ('^(%a+):'):lower();						-- get the interwiki prefix
    
    			if cfg.inter_wiki_map[prefix] then									-- if prefix is in the map, must have preceding colon
    				orig = lorig;													-- flag as error
    			end
    		end
    	end
    
    	if utilities.is_set (orig) then
    		link = '';																-- unset
    		table.insert( z.message_tail, { utilities.set_message ( 'err_bad_paramlink', orig)});	-- URL or wikilink in |title= with |title-link=;
    	end
    	
    	return link;																-- link if ok, empty string else
    end
    
    
    --[[--------------------------< C H E C K _ U R L >------------------------------------------------------------
    
    Determines whether a URL string appears to be valid.
    
    First we test for space characters.  If any are found, return false.  Then split the URL into scheme and domain
    portions, or for protocol-relative (//example.com) URLs, just the domain.  Use is_url() to validate the two
    portions of the URL.  If both are valid, or for protocol-relative if domain is valid, return true, else false.
    
    Because it is different from a standard URL, and because this module used external_link() to make external links
    that work for standard and news: links, we validate newsgroup names here.  The specification for a newsgroup name
    is at https://tools.ietf.org/html/rfc5536#section-3.1.4
    
    ]]
    
    local function check_url( url_str )
    	if nil == url_str:match ("^%S+$") then										-- if there are any spaces in |url=value it can't be a proper URL
    		return false;
    	end
    	local scheme, domain;
    
    	scheme, domain = split_url (url_str);										-- get scheme or nil and domain or nil from URL;
    	
    	if 'news:' == scheme then													-- special case for newsgroups
    		return domain:match('^[%a%d%+%-_]+%.[%a%d%+%-_%.]*[%a%d%+%-_]$');
    	end
    	
    	return is_url (scheme, domain);												-- return true if value appears to be a valid URL
    end
    
    
    --[=[-------------------------< I S _ P A R A M E T E R _ E X T _ W I K I L I N K >----------------------------
    
    Return true if a parameter value has a string that begins and ends with square brackets [ and ] and the first
    non-space characters following the opening bracket appear to be a URL.  The test will also find external wikilinks
    that use protocol-relative URLs. Also finds bare URLs.
    
    The frontier pattern prevents a match on interwiki-links which are similar to scheme:path URLs.  The tests that
    find bracketed URLs are required because the parameters that call this test (currently |title=, |chapter=, |work=,
    and |publisher=) may have wikilinks and there are articles or redirects like '//Hus' so, while uncommon, |title=[[//Hus]]
    is possible as might be [[en://Hus]].
    
    ]=]
    
    local function is_parameter_ext_wikilink (value)
    local scheme, domain;
    
    	if value:match ('%f[%[]%[%a%S*:%S+.*%]') then								-- if ext. wikilink with scheme and domain: [xxxx://yyyyy.zzz]
    		scheme, domain = split_url (value:match ('%f[%[]%[(%a%S*:%S+).*%]'));
    	elseif value:match ('%f[%[]%[//%S+.*%]') then								-- if protocol-relative ext. wikilink: [//yyyyy.zzz]
    		scheme, domain = split_url (value:match ('%f[%[]%[(//%S+).*%]'));
    	elseif value:match ('%a%S*:%S+') then										-- if bare URL with scheme; may have leading or trailing plain text
    		scheme, domain = split_url (value:match ('(%a%S*:%S+)'));
    	elseif value:match ('//%S+') then											-- if protocol-relative bare URL: //yyyyy.zzz; may have leading or trailing plain text
    		scheme, domain = split_url (value:match ('(//%S+)'));					-- what is left should be the domain
    	else
    		return false;															-- didn't find anything that is obviously a URL
    	end
    
    	return is_url (scheme, domain);												-- return true if value appears to be a valid URL
    end
    
    
    --[[-------------------------< C H E C K _ F O R _ U R L >-----------------------------------------------------
    
    loop through a list of parameters and their values.  Look at the value and if it has an external link, emit an error message.
    
    ]]
    
    local function check_for_url (parameter_list)
    local error_message = '';
    	for k, v in pairs (parameter_list) do										-- for each parameter in the list
    		if is_parameter_ext_wikilink (v) then									-- look at the value; if there is a URL add an error message
    			if utilities.is_set(error_message) then								-- once we've added the first portion of the error message ...
    				error_message = error_message .. ", ";							-- ... add a comma space separator
    			end
    			error_message = error_message .. "&#124;" .. k .. "=";				-- add the failed parameter
    		end
    	end
    	if utilities.is_set (error_message) then									-- done looping, if there is an error message, display it
    		table.insert( z.message_tail, { utilities.set_message ( 'err_param_has_ext_link', {error_message}, true ) } );
    	end
    end
    
    
    --[[--------------------------< S A F E _ F O R _ U R L >------------------------------------------------------
    
    Escape sequences for content that will be used for URL descriptions
    
    ]]
    
    local function safe_for_url( str )
    	if str:match( "%[%[.-%]%]" ) ~= nil then 
    		table.insert( z.message_tail, { utilities.set_message ( 'err_wikilink_in_url', {}, true ) } );
    	end
    	
    	return str:gsub( '[%[%]\n]', {	
    		['['] = '&#91;',
    		[']'] = '&#93;',
    		['\n'] = ' ' } );
    end
    
    
    --[[--------------------------< E X T E R N A L _ L I N K >----------------------------------------------------
    
    Format an external link with error checking
    
    ]]
    
    local function external_link( URL, label, source, access)
    	local error_str = "";
    	local domain;
    	local path;
    	local base_url;
    
    	if not utilities.is_set ( label ) then
    		label = URL;
    		if utilities.is_set ( source ) then
    			error_str = utilities.set_message ( 'err_bare_url_missing_title', { utilities.wrap_style ('parameter', source) }, false, " " );
    		else
    			error( cfg.messages["bare_url_no_origin"] );
    		end			
    	end
    	if not check_url( URL ) then
    		error_str = utilities.set_message ( 'err_bad_url', {utilities.wrap_style ('parameter', source)}, false, " " ) .. error_str;
    	end
    	
    	domain, path = URL:match ('^([/%.%-%+:%a%d]+)([/%?#].*)$');					-- split the URL into scheme plus domain and path
    	if path then																-- if there is a path portion
    		path = path:gsub ('[%[%]]', {['['] = '%5b', [']'] = '%5d'});			-- replace '[' and ']' with their percent-encoded values
    		URL = table.concat ({domain, path});									-- and reassemble
    	end
    
    	base_url = table.concat({ "[", URL, " ", safe_for_url (label), "]" });		-- assemble a wiki-markup URL
    
    	if utilities.is_set (access) then											-- access level (subscription, registration, limited)
    		base_url = utilities.substitute (cfg.presentation['ext-link-access-signal'], {cfg.presentation[access].class, cfg.presentation[access].title, base_url});	-- add the appropriate icon
    	end
    	
    	return table.concat ({base_url, error_str});
    end
    
    
    --[[--------------------------< D E P R E C A T E D _ P A R A M E T E R >--------------------------------------
    
    Categorize and emit an error message when the citation contains one or more deprecated parameters.  The function includes the
    offending parameter name to the error message.  Only one error message is emitted regardless of the number of deprecated
    parameters in the citation.
    
    added_deprecated_cat is a Boolean declared in page scope variables above
    
    ]]
    
    local function deprecated_parameter(name)
    	if not added_deprecated_cat then
    		added_deprecated_cat = true;											-- note that we've added this category
    		table.insert( z.message_tail, { utilities.set_message ( 'err_deprecated_params', {name}, true ) } );	-- add error message
    	end
    end
    
    
    --[[--------------------------< D I S C O U R A G E D _ P A R A M E T E R >------------------------------------
    
    Categorize and emit an maintenance message when the citation contains one or more discouraged parameters.  Only
    one error message is emitted regardless of the number of discouraged parameters in the citation.
    
    added_discouraged_cat is a Boolean declared in page scope variables above
    
    ]]
    
    local function discouraged_parameter(name)
    	if not added_discouraged_cat then
    		added_discouraged_cat = true;											-- note that we've added this category
    		table.insert( z.message_tail, { utilities.set_message ( 'maint_discouraged', {name}, true ) } );	-- add maint message
    	end
    end
    
    
    --[=[-------------------------< K E R N _ Q U O T E S >--------------------------------------------------------
    
    Apply kerning to open the space between the quote mark provided by the module and a leading or trailing quote
    mark contained in a |title= or |chapter= parameter's value.
    
    This function will positive kern either single or double quotes:
    	"'Unkerned title with leading and trailing single quote marks'"
    	" 'Kerned title with leading and trailing single quote marks' " (in real life the kerning isn't as wide as this example)
    Double single quotes (italic or bold wiki-markup) are not kerned.
    
    Replaces Unicode quote marks in plain text or in the label portion of a [[L|D]] style wikilink with typewriter
    quote marks regardless of the need for kerning.  Unicode quote marks are not replaced in simple [[D]] wikilinks.
    
    Call this function for chapter titles, for website titles, etc.; not for book titles.
    
    ]=]
    
    local function kern_quotes (str)
    	local cap = '';
    	local cap2 = '';
    	local wl_type, label, link;
    
    	wl_type, label, link = utilities.is_wikilink (str);							-- wl_type is: 0, no wl (text in label variable); 1, [[D]]; 2, [[L|D]]
    	
    	if 1 == wl_type then														-- [[D]] simple wikilink with or without quote marks
    		if mw.ustring.match (str, '%[%[[\"“”\'‘’].+[\"“”\'‘’]%]%]') then		-- leading and trailing quote marks
    			str = utilities.substitute (cfg.presentation['kern-wl-both'], str);
    		elseif mw.ustring.match (str, '%[%[[\"“”\'‘’].+%]%]')	then			-- leading quote marks
    			str = utilities.substitute (cfg.presentation['kern-wl-left'], str);
    		elseif mw.ustring.match (str, '%[%[.+[\"“”\'‘’]%]%]') then				-- trailing quote marks
    			str = utilities.substitute (cfg.presentation['kern-wl-right'], str);
    		end
    
    	else																		-- plain text or [[L|D]]; text in label variable
    		label = mw.ustring.gsub (label, '[“”]', '\"');							-- replace “” (U+201C & U+201D) with " (typewriter double quote mark)
    		label = mw.ustring.gsub (label, '[‘’]', '\'');							-- replace ‘’ (U+2018 & U+2019) with ' (typewriter single quote mark)
    
    		cap, cap2 = mw.ustring.match (label, "^([\"\'])([^\'].+)");				-- match leading double or single quote but not doubled single quotes (italic markup)
    		if utilities.is_set (cap) then
    			label = utilities.substitute (cfg.presentation['kern-left'], {cap, cap2});
    		end
    	
    		cap, cap2 = mw.ustring.match (label, "^(.+[^\'])([\"\'])$")				-- match trailing double or single quote but not doubled single quotes (italic markup)
    		if utilities.is_set (cap) then
    			label = utilities.substitute (cfg.presentation['kern-right'], {cap, cap2});
    		end
    		
    		if 2 == wl_type then
    			str = utilities.make_wikilink (link, label);						-- reassemble the wikilink
    		else
    			str = label;
    		end
    	end
    	return str;
    end
    
    
    --[[--------------------------< F O R M A T _ S C R I P T _ V A L U E >----------------------------------------
    
    |script-title= holds title parameters that are not written in Latin-based scripts: Chinese, Japanese, Arabic, Hebrew, etc. These scripts should
    not be italicized and may be written right-to-left.  The value supplied by |script-title= is concatenated onto Title after Title has been wrapped
    in italic markup.
    
    Regardless of language, all values provided by |script-title= are wrapped in <bdi>...</bdi> tags to isolate RTL languages from the English left to right.
    
    |script-title= provides a unique feature.  The value in |script-title= may be prefixed with a two-character ISO 639-1 language code and a colon:
    	|script-title=ja:*** *** (where * represents a Japanese character)
    Spaces between the two-character code and the colon and the colon and the first script character are allowed:
    	|script-title=ja : *** ***
    	|script-title=ja: *** ***
    	|script-title=ja :*** ***
    Spaces preceding the prefix are allowed: |script-title = ja:*** ***
    
    The prefix is checked for validity.  If it is a valid ISO 639-1 language code, the lang attribute (lang="ja") is added to the <bdi> tag so that browsers can
    know the language the tag contains.  This may help the browser render the script more correctly.  If the prefix is invalid, the lang attribute
    is not added.  At this time there is no error message for this condition.
    
    Supports |script-title=, |script-chapter=, |script-<periodical>=
    
    ]]
    
    local function format_script_value (script_value, script_param)
    	local lang='';																-- initialize to empty string
    	local name;
    	if script_value:match('^%l%l%l?%s*:') then									-- if first 3 or 4 non-space characters are script language prefix
    		lang = script_value:match('^(%l%l%l?)%s*:%s*%S.*');						-- get the language prefix or nil if there is no script
    		if not utilities.is_set (lang) then
    			table.insert( z.message_tail, { utilities.set_message ( 'err_script_parameter', {script_param, 'missing title part'}, true ) } );		-- prefix without 'title'; add error message
    			return '';															-- script_value was just the prefix so return empty string
    		end
    																				-- if we get this far we have prefix and script
    		name = cfg.lang_code_remap[lang] or mw.language.fetchLanguageName( lang, cfg.this_wiki_code );	-- get language name so that we can use it to categorize
    		if utilities.is_set (name) then											-- is prefix a proper ISO 639-1 language code?
    			script_value = script_value:gsub ('^%l+%s*:%s*', '');				-- strip prefix from script
    																				-- is prefix one of these language codes?
    			if utilities.in_array (lang, cfg.script_lang_codes) then
    				utilities.add_prop_cat ('script_with_name', {name, lang})
    			else
    				table.insert( z.message_tail, { utilities.set_message ( 'err_script_parameter', {script_param, 'unknown language code'}, true ) } );	-- unknown script-language; add error message
    			end
    			lang = ' lang="' .. lang .. '" ';									-- convert prefix into a lang attribute
    		else
    			table.insert( z.message_tail, { utilities.set_message ( 'err_script_parameter', {script_param, 'invalid language code'}, true ) } );		-- invalid language code; add error message
    			lang = '';															-- invalid so set lang to empty string
    		end
    	else
    		table.insert( z.message_tail, { utilities.set_message ( 'err_script_parameter', {script_param, 'missing prefix'}, true ) } );				-- no language code prefix; add error message
    	end
    	script_value = utilities.substitute (cfg.presentation['bdi'], {lang, script_value});	-- isolate in case script is RTL
    
    	return script_value;
    end
    
    
    --[[--------------------------< S C R I P T _ C O N C A T E N A T E >------------------------------------------
    
    Initially for |title= and |script-title=, this function concatenates those two parameter values after the script value has been 
    wrapped in <bdi> tags.
    ]]
    
    local function script_concatenate (title, script, script_param)
    	if utilities.is_set (script) then
    		script = format_script_value (script, script_param);					-- <bdi> tags, lang attribute, categorization, etc.; returns empty string on error
    		if utilities.is_set (script) then
    			title = title .. ' ' .. script;										-- concatenate title and script title
    		end
    	end
    	return title;
    end
    
    
    --[[--------------------------< W R A P _ M S G >--------------------------------------------------------------
    
    Applies additional message text to various parameter values. Supplied string is wrapped using a message_list
    configuration taking one argument.  Supports lower case text for {{citation}} templates.  Additional text taken
    from citation_config.messages - the reason this function is similar to but separate from wrap_style().
    
    ]]
    
    local function wrap_msg (key, str, lower)
    	if not utilities.is_set ( str ) then
    		return "";
    	end
    	if true == lower then
    		local msg;
    		msg = cfg.messages[key]:lower();										-- set the message to lower case before 
    		return utilities.substitute ( msg, str );								-- including template text
    	else
    		return utilities.substitute ( cfg.messages[key], str );
    	end		
    end
    
    
    --[[----------------< W I K I S O U R C E _ U R L _ M A K E >-------------------
    
    Makes a Wikisource URL from Wikisource interwiki-link.  Returns the URL and appropriate
    label; nil else.
    
    str is the value assigned to |chapter= (or aliases) or |title= or |title-link=
    
    ]]
    
    local function wikisource_url_make (str)
    	local wl_type, D, L;
    	local ws_url, ws_label;
    	local wikisource_prefix = table.concat ({'https://', cfg.this_wiki_code, '.wikisource.org/wiki/'});
    
    	wl_type, D, L = utilities.is_wikilink (str);								-- wl_type is 0 (not a wikilink), 1 (simple wikilink), 2 (complex wikilink)
    
    	if 0 == wl_type then														-- not a wikilink; might be from |title-link=
    		str = D:match ('^[Ww]ikisource:(.+)') or D:match ('^[Ss]:(.+)');		-- article title from interwiki link with long-form or short-form namespace
    		if utilities.is_set (str) then
    			ws_url = table.concat ({											-- build a Wikisource URL
    				wikisource_prefix,												-- prefix
    				str,															-- article title
    				});
    			ws_label = str;														-- label for the URL
    		end
    	elseif 1 == wl_type then													-- simple wikilink: [[Wikisource:ws article]]
    		str = D:match ('^[Ww]ikisource:(.+)') or D:match ('^[Ss]:(.+)');		-- article title from interwiki link with long-form or short-form namespace
    		if utilities.is_set (str) then
    			ws_url = table.concat ({											-- build a Wikisource URL
    				wikisource_prefix,												-- prefix
    				str,															-- article title
    				});
    			ws_label = str;														-- label for the URL
    		end
    	elseif 2 == wl_type then													-- non-so-simple wikilink: [[Wikisource:ws article|displayed text]] ([[L|D]])
    		str = L:match ('^[Ww]ikisource:(.+)') or L:match ('^[Ss]:(.+)');		-- article title from interwiki link with long-form or short-form namespace
    		if utilities.is_set (str) then
    			ws_label = D;														-- get ws article name from display portion of interwiki link
    			ws_url = table.concat ({											-- build a Wikisource URL
    				wikisource_prefix,												-- prefix
    				str,															-- article title without namespace from link portion of wikilink
    				});
    		end
    	end
    
    	if ws_url then
    		ws_url = mw.uri.encode (ws_url, 'WIKI');								-- make a usable URL
    		ws_url = ws_url:gsub ('%%23', '#');										-- undo percent-encoding of fragment marker
    	end
    
    	return ws_url, ws_label, L or D;											-- return proper URL or nil and a label or nil
    end
    
    
    --[[----------------< F O R M A T _ P E R I O D I C A L >-----------------------
    
    Format the three periodical parameters: |script-<periodical>=, |<periodical>=,
    and |trans-<periodical>= into a single Periodical meta-parameter.
    
    ]]
    
    local function format_periodical (script_periodical, script_periodical_source, periodical, trans_periodical)
    	local periodical_error = '';
    
    	if not utilities.is_set (periodical) then
    		periodical = '';														-- to be safe for concatenation
    	else
    		periodical = utilities.wrap_style ('italic-title', periodical);			-- style 
    	end
    
    	periodical = script_concatenate (periodical, script_periodical, script_periodical_source);	-- <bdi> tags, lang attribute, categorization, etc.; must be done after title is wrapped
    
    	if utilities.is_set (trans_periodical) then
    		trans_periodical = utilities.wrap_style ('trans-italic-title', trans_periodical);
    		if utilities.is_set (periodical) then
    			periodical = periodical .. ' ' .. trans_periodical;
    		else																	-- here when trans-periodical without periodical or script-periodical
    			periodical = trans_periodical;
    			periodical_error = ' ' .. utilities.set_message ('err_trans_missing_title', {'periodical'});
    		end
    	end
    
    	return periodical .. periodical_error;
    end
    
    
    --[[------------------< F O R M A T _ C H A P T E R _ T I T L E >---------------
    
    Format the four chapter parameters: |script-chapter=, |chapter=, |trans-chapter=,
    and |chapter-url= into a single chapter meta- parameter (chapter_url_source used
    for error messages).
    
    ]]
    
    local function format_chapter_title (script_chapter, script_chapter_source, chapter, chapter_source, trans_chapter, trans_chapter_source, chapter_url, chapter_url_source, no_quotes, access)
    	local chapter_error = '';
    
    	local ws_url, ws_label, L = wikisource_url_make (chapter);					-- make a wikisource URL and label from a wikisource interwiki link
    	if ws_url then
    		ws_label = ws_label:gsub ('_', ' ');									-- replace underscore separators with space characters
    		chapter = ws_label;
    	end
    
    	if not utilities.is_set (chapter) then
    		chapter = '';															-- to be safe for concatenation
    	else
    		if false == no_quotes then
    			chapter = kern_quotes (chapter);									-- if necessary, separate chapter title's leading and trailing quote marks from module provided quote marks
    			chapter = utilities.wrap_style ('quoted-title', chapter);
    		end
    	end
    
    	chapter = script_concatenate (chapter, script_chapter, script_chapter_source);	-- <bdi> tags, lang attribute, categorization, etc.; must be done after title is wrapped
    
    	if utilities.is_set (chapter_url) then
    		chapter = external_link (chapter_url, chapter, chapter_url_source, access);	-- adds bare_url_missing_title error if appropriate
    	elseif ws_url then
    		chapter = external_link (ws_url, chapter .. '&nbsp;', 'ws link in chapter');	-- adds bare_url_missing_title error if appropriate; space char to move icon away from chap text; TODO: better way to do this?
    		chapter = utilities.substitute (cfg.presentation['interwiki-icon'], {cfg.presentation['class-wikisource'], L, chapter});				
    	end
    
    	if utilities.is_set (trans_chapter) then
    		trans_chapter = utilities.wrap_style ('trans-quoted-title', trans_chapter);
    		if utilities.is_set (chapter) then
    			chapter = chapter .. ' ' .. trans_chapter;
    		else																	-- here when trans_chapter without chapter or script-chapter
    			chapter = trans_chapter;
    			chapter_source = trans_chapter_source:match ('trans%-?(.+)');		-- when no chapter, get matching name from trans-<param>
    			chapter_error = ' ' .. utilities.set_message ('err_trans_missing_title', {chapter_source});
    		end
    	end
    
    	return chapter .. chapter_error;
    end
    
    
    --[[----------------< H A S _ I N V I S I B L E _ C H A R S >-------------------
    
    This function searches a parameter's value for non-printable or invisible characters.
    The search stops at the first match.
    
    This function will detect the visible replacement character when it is part of the Wikisource.
    
    Detects but ignores nowiki and math stripmarkers.  Also detects other named stripmarkers
    (gallery, math, pre, ref) and identifies them with a slightly different error message.
    See also coins_cleanup().
    
    Output of this function is an error message that identifies the character or the
    Unicode group, or the stripmarker that was detected along with its position (or,
    for multi-byte characters, the position of its first byte) in the parameter value.
    
    ]]
    
    local function has_invisible_chars (param, v)
    	local position = '';														-- position of invisible char or starting position of stripmarker
    	local capture;																-- used by stripmarker detection to hold name of the stripmarker
    	local stripmarker;															-- boolean set true when a stripmarker is found
    
    	capture = string.match (v, '[%w%p ]*');										-- test for values that are simple ASCII text and bypass other tests if true
    	if capture == v then														-- if same there are no Unicode characters
    		return;
    	end
    
    	for _, invisible_char in ipairs (cfg.invisible_chars) do
    		local char_name = invisible_char[1];									-- the character or group name
    		local pattern = invisible_char[2];										-- the pattern used to find it
    		position, _, capture = mw.ustring.find (v, pattern);					-- see if the parameter value contains characters that match the pattern
    		
    		if position and (cfg.invisible_defs.zwj == capture) then				-- if we found a zero-width joiner character
    			if mw.ustring.find (v, cfg.indic_script) then						-- it's ok if one of the Indic scripts
    				position = nil;													-- unset position
    			elseif cfg.emoji[mw.ustring.codepoint (v, position+1)] then			-- is zwj followed by a character listed in emoji{}?
    				position = nil;													-- unset position
    			end
    		end
    		
    		if position then
    			if 'nowiki' == capture or 'math' == capture or						-- nowiki and math stripmarkers (not an error condition)
    				('templatestyles' == capture and utilities.in_array (param, {'id', 'quote'})) then	-- templatestyles stripmarker allowed in these parameters
    					stripmarker = true;											-- set a flag
    			elseif true == stripmarker and cfg.invisible_defs.del == capture then	-- because stripmakers begin and end with the delete char, assume that we've found one end of a stripmarker
    				position = nil;													-- unset
    			else
    				local err_msg;
    				if capture and not (cfg.invisible_defs.del == capture or cfg.invisible_defs.zwj == capture) then
    					err_msg = capture .. ' ' .. char_name;
    				else
    					err_msg = char_name .. ' ' .. 'character';
    				end
    
    				table.insert (z.message_tail, {utilities.set_message ('err_invisible_char', {err_msg, utilities.wrap_style ('parameter', param), position}, true)});	-- add error message
    				return;															-- and done with this parameter
    			end
    		end
    	end
    end
    
    
    --[[-------------------< A R G U M E N T _ W R A P P E R >----------------------
    
    Argument wrapper.  This function provides support for argument mapping defined
    in the configuration file so that multiple names can be transparently aliased to
    single internal variable.
    
    ]]
    
    local function argument_wrapper ( args )
    	local origin = {};
    	
    	return setmetatable({
    		ORIGIN = function ( self, k )
    			local dummy = self[k];												-- force the variable to be loaded.
    			return origin[k];
    		end
    	},
    	{
    		__index = function ( tbl, k )
    			if origin[k] ~= nil then
    				return nil;
    			end
    			
    			local args, list, v = args, cfg.aliases[k];
    			
    			if type( list ) == 'table' then
    				v, origin[k] = utilities.select_one ( args, list, 'err_redundant_parameters' );
    				if origin[k] == nil then
    					origin[k] = '';												-- Empty string, not nil
    				end
    			elseif list ~= nil then
    				v, origin[k] = args[list], list;
    			else
    				-- maybe let through instead of raising an error?
    				-- v, origin[k] = args[k], k;
    				error( cfg.messages['unknown_argument_map'] .. ': ' .. k);
    			end
    			
    			-- Empty strings, not nil;
    			if v == nil then
    				v = '';
    				origin[k] = '';
    			end
    			
    			tbl = rawset( tbl, k, v );
    			return v;
    		end,
    	});
    end
    
    
    --[[--------------------------< N O W R A P _ D A T E >-------------------------
    
    When date is YYYY-MM-DD format wrap in nowrap span: <span ...>YYYY-MM-DD</span>.
    When date is DD MMMM YYYY or is MMMM DD, YYYY then wrap in nowrap span:
    <span ...>DD MMMM</span> YYYY or <span ...>MMMM DD,</span> YYYY
    
    DOES NOT yet support MMMM YYYY or any of the date ranges.
    
    ]]
    
    local function nowrap_date (date)
    	local cap = '';
    	local cap2 = '';
    
    	if date:match("^%d%d%d%d%-%d%d%-%d%d$") then
    		date = utilities.substitute (cfg.presentation['nowrap1'], date);
    	
    	elseif date:match("^%a+%s*%d%d?,%s+%d%d%d%d$") or date:match ("^%d%d?%s*%a+%s+%d%d%d%d$") then
    		cap, cap2 = string.match (date, "^(.*)%s+(%d%d%d%d)$");
    		date = utilities.substitute (cfg.presentation['nowrap2'], {cap, cap2});
    	end
    	
    	return date;
    end
    
    
    --[[--------------------------< S E T _ T I T L E T Y P E >---------------------
    
    This function sets default title types (equivalent to the citation including
    |type=<default value>) for those templates that have defaults. Also handles the
    special case where it is desirable to omit the title type from the rendered citation
    (|type=none).
    
    ]]
    
    local function set_titletype (cite_class, title_type)
    	if utilities.is_set (title_type) then
    		if 'none' == cfg.keywords_xlate[title_type] then
    			title_type = '';													-- if |type=none then type parameter not displayed
    		end
    		return title_type;														-- if |type= has been set to any other value use that value
    	end
    
    	return cfg.title_types [cite_class] or '';									-- set template's default title type; else empty string for concatenation
    end
    
    
    --[[--------------------------< H Y P H E N _ T O _ D A S H >--------------------------------------------------
    
    Converts a hyphen to a dash under certain conditions.  The hyphen must separate
    like items; unlike items are returned unmodified.  These forms are modified:
    	letter - letter (A - B)
    	digit - digit (4-5)
    	digit separator digit - digit separator digit (4.1-4.5 or 4-1-4-5)
    	letterdigit - letterdigit (A1-A5) (an optional separator between letter and
    		digit is supported – a.1-a.5 or a-1-a-5)
    	digitletter - digitletter (5a - 5d) (an optional separator between letter and
    		digit is supported – 5.a-5.d or 5-a-5-d)
    
    any other forms are returned unmodified.
    
    str may be a comma- or semicolon-separated list
    
    ]]
    
    local function hyphen_to_dash( str )
    	if not utilities.is_set (str) then
    		return str;
    	end
    
    	local accept; -- Boolean
    
    	str = str:gsub ('&[nm]dash;', {['&ndash;'] = '–', ['&mdash;'] = '—'});		-- replace &mdash; and &ndash; entities with their characters; semicolon mucks up the text.split
    	str = str:gsub ('&#45;', '-'); -- replace HTML numeric entity with hyphen character
    
    	str = str:gsub ('&nbsp;', ' '); -- replace &nbsp; entity with generic keyboard space character
    	
    	local out = {};
    	local list = mw.text.split (str, '%s*[,;]%s*');								-- split str at comma or semicolon separators if there are any
    
    	for _, item in ipairs (list) do												-- for each item in the list
    		item, accept = utilities.has_accept_as_written (item);					-- remove accept-this-as-written markup when it wraps all of item
    		if not accept and mw.ustring.match (item, '^%w*[%.%-]?%w+%s*[%-–—]%s*%w*[%.%-]?%w+$') then	-- if a hyphenated range or has endash or emdash separators
    			if item:match ('^%a+[%.%-]?%d+%s*%-%s*%a+[%.%-]?%d+$') or			-- letterdigit hyphen letterdigit (optional separator between letter and digit)
    				item:match ('^%d+[%.%-]?%a+%s*%-%s*%d+[%.%-]?%a+$') or			-- digitletter hyphen digitletter (optional separator between digit and letter)
    				item:match ('^%d+[%.%-]%d+%s*%-%s*%d+[%.%-]%d+$') or			-- digit separator digit hyphen digit separator digit
    				item:match ('^%d+%s*%-%s*%d+$') or								-- digit hyphen digit
    				item:match ('^%a+%s*%-%s*%a+$') then							-- letter hyphen letter
    					item = item:gsub ('(%w*[%.%-]?%w+)%s*%-%s*(%w*[%.%-]?%w+)', '%1–%2');	-- replace hyphen, remove extraneous space characters
    			else
    				item = mw.ustring.gsub (item, '%s*[–—]%s*', '–');				-- for endash or emdash separated ranges, replace em with en, remove extraneous whitespace
    			end
    		end
    		table.insert (out, item);												-- add the (possibly modified) item to the output table
    	end
    
    	local temp_str = '';														-- concatenate the output table into a comma separated string
    	temp_str, accept = utilities.has_accept_as_written (table.concat (out, ', ')); -- remove accept-this-as-written markup when it wraps all of concatenated out
    	if accept then
    		temp_str = utilities.has_accept_as_written (str);						-- when global markup removed, return original str; do it this way to suppress boolean second return value
    		return temp_str;
    	else
    		return temp_str;														-- else, return assembled temp_str
    	end
    end
    
    
    --[[--------------------------< S A F E _ J O I N >-----------------------------
    
    Joins a sequence of strings together while checking for duplicate separation characters.
    
    ]]
    
    local function safe_join( tbl, duplicate_char )
    	local f = {};																-- create a function table appropriate to type of 'duplicate character'
    		if 1 == #duplicate_char then											-- for single byte ASCII characters use the string library functions
    			f.gsub = string.gsub
    			f.match = string.match
    			f.sub = string.sub
    		else																	-- for multi-byte characters use the ustring library functions
    			f.gsub = mw.ustring.gsub
    			f.match = mw.ustring.match
    			f.sub = mw.ustring.sub
    		end
    
    	local str = '';																-- the output string
    	local comp = '';															-- what does 'comp' mean?
    	local end_chr = '';
    	local trim;
    	for _, value in ipairs( tbl ) do
    		if value == nil then value = ''; end
    		
    		if str == '' then														-- if output string is empty
    			str = value;														-- assign value to it (first time through the loop)
    		elseif value ~= '' then
    			if value:sub(1, 1) == '<' then										-- special case of values enclosed in spans and other markup.
    				comp = value:gsub( "%b<>", "" );								-- remove HTML markup (<span>string</span> -> string)
    			else
    				comp = value;
    			end
    																				-- typically duplicate_char is sepc
    			if f.sub(comp, 1, 1) == duplicate_char then							-- is first character same as duplicate_char? why test first character?
    																				--   Because individual string segments often (always?) begin with terminal punct for the
    																				--   preceding segment: 'First element' .. 'sepc next element' .. etc.?
    				trim = false;
    				end_chr = f.sub(str, -1, -1);									-- get the last character of the output string
    				-- str = str .. "<HERE(enchr=" .. end_chr .. ")"				-- debug stuff?
    				if end_chr == duplicate_char then								-- if same as separator
    					str = f.sub(str, 1, -2);									-- remove it
    				elseif end_chr == "'" then										-- if it might be wiki-markup
    					if f.sub(str, -3, -1) == duplicate_char .. "''" then		-- if last three chars of str are sepc'' 
    						str = f.sub(str, 1, -4) .. "''";						-- remove them and add back ''
    					elseif  f.sub(str, -5, -1) == duplicate_char .. "]]''" then	-- if last five chars of str are sepc]]'' 
    						trim = true;											-- why? why do this and next differently from previous?
    					elseif f.sub(str, -4, -1) == duplicate_char .. "]''" then	-- if last four chars of str are sepc]'' 
    						trim = true;											-- same question
    					end
    				elseif end_chr == "]" then										-- if it might be wiki-markup
    					if f.sub(str, -3, -1) == duplicate_char .. "]]" then		-- if last three chars of str are sepc]] wikilink 
    						trim = true;
    					elseif f.sub(str, -3, -1) == duplicate_char .. '"]' then	-- if last three chars of str are sepc"] quoted external link 
    						trim = true;
    					elseif  f.sub(str, -2, -1) == duplicate_char .. "]" then	-- if last two chars of str are sepc] external link
    						trim = true;
    					elseif f.sub(str, -4, -1) == duplicate_char .. "'']" then	-- normal case when |url=something & |title=Title.
    						trim = true;
    					end
    				elseif end_chr == " " then										-- if last char of output string is a space
    					if f.sub(str, -2, -1) == duplicate_char .. " " then			-- if last two chars of str are <sepc><space>
    						str = f.sub(str, 1, -3);								-- remove them both
    					end
    				end
    
    				if trim then
    					if value ~= comp then 										-- value does not equal comp when value contains HTML markup
    						local dup2 = duplicate_char;
    						if f.match(dup2, "%A" ) then dup2 = "%" .. dup2; end	-- if duplicate_char not a letter then escape it
    						
    						value = f.gsub(value, "(%b<>)" .. dup2, "%1", 1 )		-- remove duplicate_char if it follows HTML markup
    					else
    						value = f.sub(value, 2, -1 );							-- remove duplicate_char when it is first character
    					end
    				end
    			end
    			str = str .. value; 												-- add it to the output string
    		end
    	end
    	return str;
    end
    
    
    --[[--------------------------< I S _ S U F F I X >-----------------------------
    
    returns true is suffix is properly formed Jr, Sr, or ordinal in the range 1–9.
    Puncutation not allowed.
    
    ]]
    
    local function is_suffix (suffix)
    	if utilities.in_array (suffix, {'Jr', 'Sr', 'Jnr', 'Snr', '1st', '2nd', '3rd'}) or suffix:match ('^%dth$') then
    		return true;
    	end
    	return false;
    end
    
    
    --[[--------------------< I S _ G O O D _ V A N C _ N A M E >-------------------
    
    For Vancouver style, author/editor names are supposed to be rendered in Latin
    (read ASCII) characters.  When a name uses characters that contain diacritical
    marks, those characters are to be converted to the corresponding Latin
    character. When a name is written using a non-Latin alphabet or logogram, that
    name is to be transliterated into Latin characters. The module doesn't do this
    so editors may/must.
    
    This test allows |first= and |last= names to contain any of the letters defined
    in the four Unicode Latin character sets
    	[http://www.unicode.org/charts/PDF/U0000.pdf C0 Controls and Basic Latin] 0041–005A, 0061–007A
    	[http://www.unicode.org/charts/PDF/U0080.pdf C1 Controls and Latin-1 Supplement] 00C0–00D6, 00D8–00F6, 00F8–00FF
    	[http://www.unicode.org/charts/PDF/U0100.pdf Latin Extended-A] 0100–017F
    	[http://www.unicode.org/charts/PDF/U0180.pdf Latin Extended-B] 0180–01BF, 01C4–024F
    
    |lastn= also allowed to contain hyphens, spaces, and apostrophes.
    	(http://www.ncbi.nlm.nih.gov/books/NBK7271/box/A35029/)
    |firstn= also allowed to contain hyphens, spaces, apostrophes, and periods
    
    This original test:
    	if nil == mw.ustring.find (last, "^[A-Za-zÀ-ÖØ-öø-ƿDŽ-ɏ%-%s%']*$")
    	or nil == mw.ustring.find (first, "^[A-Za-zÀ-ÖØ-öø-ƿDŽ-ɏ%-%s%'%.]+[2-6%a]*$") then
    was written outside of the code editor and pasted here because the code editor
    gets confused between character insertion point and cursor position. The test has
    been rewritten to use decimal character escape sequence for the individual bytes
    of the Unicode characters so that it is not necessary to use an external editor
    to maintain this code.
    
    	\195\128-\195\150 – À-Ö (U+00C0–U+00D6 – C0 controls)
    	\195\152-\195\182 – Ø-ö (U+00D8-U+00F6 – C0 controls)
    	\195\184-\198\191 – ø-ƿ (U+00F8-U+01BF – C0 controls, Latin extended A & B)
    	\199\132-\201\143 – DŽ-ɏ (U+01C4-U+024F – Latin extended B)
    
    ]]
    
    local function is_good_vanc_name (last, first, suffix, position)
    	if not suffix then
    		if first:find ('[,%s]') then											-- when there is a space or comma, might be first name/initials + generational suffix
    			first = first:match ('(.-)[,%s]+');									-- get name/initials
    			suffix = first:match ('[,%s]+(.+)$');								-- get generational suffix
    		end
    	end
    	if utilities.is_set (suffix) then
    		if not is_suffix (suffix) then
    			add_vanc_error (cfg.err_msg_supl.suffix, position);
    			return false;														-- not a name with an appropriate suffix
    		end
    	end
    	if nil == mw.ustring.find (last, "^[A-Za-z\195\128-\195\150\195\152-\195\182\195\184-\198\191\199\132-\201\143%-%s%']*$") or
    		nil == mw.ustring.find (first, "^[A-Za-z\195\128-\195\150\195\152-\195\182\195\184-\198\191\199\132-\201\143%-%s%'%.]*$") then
    			add_vanc_error (cfg.err_msg_supl['non-Latin char'], position);
    			return false;														-- not a string of Latin characters; Vancouver requires Romanization
    	end;
    	return true;
    end
    
    
    --[[--------------------------< R E D U C E _ T O _ I N I T I A L S >------------------------------------------
    
    Attempts to convert names to initials in support of |name-list-style=vanc.  
    
    Names in |firstn= may be separated by spaces or hyphens, or for initials, a period.
    See http://www.ncbi.nlm.nih.gov/books/NBK7271/box/A35062/.
    
    Vancouver style requires family rank designations (Jr, II, III, etc.) to be rendered
    as Jr, 2nd, 3rd, etc.  See http://www.ncbi.nlm.nih.gov/books/NBK7271/box/A35085/.
    This code only accepts and understands generational suffix in the Vancouver format
    because Roman numerals look like, and can be mistaken for, initials.
    
    This function uses ustring functions because firstname initials may be any of the
    Unicode Latin characters accepted by is_good_vanc_name ().
    
    ]]
    
    local function reduce_to_initials(first, position)
    	local name, suffix = mw.ustring.match(first, "^(%u+) ([%dJS][%drndth]+)$");
    
    	if not name then															-- if not initials and a suffix
    		name = mw.ustring.match(first, "^(%u+)$");								-- is it just initials?
    	end
    
    	if name then																-- if first is initials with or without suffix
    		if 3 > mw.ustring.len (name) then										-- if one or two initials
    			if suffix then														-- if there is a suffix
    				if is_suffix (suffix) then										-- is it legitimate?
    					return first;												-- one or two initials and a valid suffix so nothing to do
    				else
    					add_vanc_error (cfg.err_msg_supl.suffix, position);			-- one or two initials with invalid suffix so error message
    					return first;												-- and return first unmolested
    				end
    			else
    				return first;													-- one or two initials without suffix; nothing to do
    			end
    		end
    	end																			-- if here then name has 3 or more uppercase letters so treat them as a word
    
    	local initials, names = {}, {};												-- tables to hold name parts and initials
    	local i = 1;																-- counter for number of initials
    
    	names = mw.text.split (first, '[%s,]+');									-- split into a table of names and possible suffix
    
    	while names[i] do															-- loop through the table
    		if 1 < i and names[i]:match ('[%dJS][%drndth]+%.?$') then				-- if not the first name, and looks like a suffix (may have trailing dot)
    			names[i] = names[i]:gsub ('%.', '');								-- remove terminal dot if present
    			if is_suffix (names[i]) then										-- if a legitimate suffix
    				table.insert (initials, ' ' .. names[i]);						-- add a separator space, insert at end of initials table
    				break;															-- and done because suffix must fall at the end of a name
    			end																	-- no error message if not a suffix; possibly because of Romanization
    		end
    		if 3 > i then
    			table.insert (initials, mw.ustring.sub(names[i], 1, 1));			-- insert the initial at end of initials table
    		end
    		i = i + 1;																-- bump the counter
    	end
    			
    	return table.concat(initials)												-- Vancouver format does not include spaces.
    end
    
    
    --[[--------------------------< L I S T _ P E O P L E >--------------------------
    
    Formats a list of people (authors, contributors, editors, interviewers, translators) 
    
    names in the list will be linked when
    	|<name>-link= has a value
    	|<name>-mask- does NOT have a value; masked names are presumed to have been
    		rendered previously so should have been linked there
    
    when |<name>-mask=0, the associated name is not rendered
    
    ]]
    
    local function list_people (control, people, etal)
    	local sep;
    	local namesep;
    	local format = control.format;
    	local maximum = control.maximum;
    	local name_list = {};
    
    	if 'vanc' == format then													-- Vancouver-like name styling?
    		sep = cfg.presentation['sep_nl_vanc'];									-- name-list separator between names is a comma
    		namesep = cfg.presentation['sep_name_vanc'];							-- last/first separator is a space
    	else
    		sep = cfg.presentation['sep_nl'];										-- name-list separator between names is a semicolon
    		namesep = cfg.presentation['sep_name'];									-- last/first separator is <comma><space>
    	end
    	
    	if sep:sub (-1, -1) ~= " " then sep = sep .. " " end
    	if utilities.is_set (maximum) and maximum < 1 then return "", 0; end		-- returned 0 is for EditorCount; not used for other names
    	
    	for i, person in ipairs (people) do
    		if utilities.is_set (person.last) then
    			local mask = person.mask;
    			local one;
    			local sep_one = sep;
    
    			if utilities.is_set (maximum) and i > maximum then
    				etal = true;
    				break;
    			end
    			
    			if mask then
    				local n = tonumber (mask);										-- convert to a number if it can be converted; nil else
    				if n then
    					one = 0 ~= n and string.rep("&mdash;", n) or nil;			-- make a string of (n > 0) mdashes, nil else, to replace name
    					person.link = nil;											-- don't create link to name if name is replaces with mdash string or has been set nil
    				else
    					one = mask;													-- replace name with mask text (must include name-list separator)
    					sep_one = " ";												-- modify name-list separator
    				end
    			else
    				one = person.last;												-- get surname
    				local first = person.first										-- get given name
    				if utilities.is_set (first) then
    					if ("vanc" == format) then									-- if Vancouver format
    						one = one:gsub ('%.', '');								-- remove periods from surnames (http://www.ncbi.nlm.nih.gov/books/NBK7271/box/A35029/)
    						if not person.corporate and is_good_vanc_name (one, first, nil, i) then		-- and name is all Latin characters; corporate authors not tested
    							first = reduce_to_initials (first, i);				-- attempt to convert first name(s) to initials
    						end
    					end
    					one = one .. namesep .. first;
    				end
    			end
    			if utilities.is_set (person.link) then
    				one = utilities.make_wikilink (person.link, one);				-- link author/editor
    			end
    			if one then															-- if <one> has a value (name, mdash replacement, or mask text replacement)
    				table.insert (name_list, one);									-- add it to the list of names
    				table.insert (name_list, sep_one);								-- add the proper name-list separator
    			end
    		end
    	end
    
    	local count = #name_list / 2;												-- (number of names + number of separators) divided by 2
    	if 0 < count then 
    		if 1 < count and not etal then
    			if 'amp' == format then
    				name_list[#name_list-2] = " & ";								-- replace last separator with ampersand text
    			elseif 'and' == format then
    				if 2 == count then
    					name_list[#name_list-2] = cfg.presentation.sep_nl_and;		-- replace last separator with 'and' text
    				else
    					name_list[#name_list-2] = cfg.presentation.sep_nl_end;		-- replace last separator with '(sep) and' text
    				end
    			end
    		end
    		name_list[#name_list] = nil;											-- erase the last separator
    	end
    
    	local result = table.concat (name_list);									-- construct list
    	if etal and utilities.is_set (result) then									-- etal may be set by |display-authors=etal but we might not have a last-first list
    		result = result .. sep .. ' ' .. cfg.messages['et al'];					-- we've got a last-first list and etal so add et al.
    	end
    	
    	return result, count;														-- return name-list string and count of number of names (count used for editor names only)
    end
    
    --[[--------------------< M A K E _ C I T E R E F _ I D >-----------------------
    
    Generates a CITEREF anchor ID if we have at least one name or a date.  Otherwise
    returns an empty string.
    
    namelist is one of the contributor-, author-, or editor-name lists chosen in that
    order.  year is Year or anchor_year.
    
    ]]
    
    local function make_citeref_id (namelist, year)
    	local names={};							-- a table for the one to four names and year
    	for i,v in ipairs (namelist) do			-- loop through the list and take up to the first four last names
    		names[i] = v.last
    		if i == 4 then break end			-- if four then done
    	end
    	table.insert (names, year);				-- add the year at the end
    	local id = table.concat(names);			-- concatenate names and year for CITEREF id
    	if utilities.is_set (id) then			-- if concatenation is not an empty string
    		return "CITEREF" .. id;				-- add the CITEREF portion
    	else
    		return '';							-- return an empty string; no reason to include CITEREF id in this citation
    	end
    end
    
    
    --[[---------------------< N A M E _ H A S _ E T A L >--------------------------
    
    Evaluates the content of name parameters (author, editor, etc.) for variations on
    the theme of et al.  If found, the et al. is removed, a flag is set to true and
    the function returns the modified name and the flag.
    
    This function never sets the flag to false but returns its previous state because
    it may have been set by previous passes through this function or by the associated
    |display-<names>=etal parameter
    
    ]]
    
    local function name_has_etal (name, etal, nocat, param)
    
    	if utilities.is_set (name) then												-- name can be nil in which case just return
    		local patterns = cfg.et_al_patterns; 									-- get patterns from configuration
    		
    		for _, pattern in ipairs (patterns) do									-- loop through all of the patterns
    			if name:match (pattern) then										-- if this 'et al' pattern is found in name
    				name = name:gsub (pattern, '');									-- remove the offending text
    				etal = true;													-- set flag (may have been set previously here or by |display-<names>=etal)
    				if not nocat then												-- no categorization for |vauthors=
    					table.insert( z.message_tail, {utilities.set_message ('err_etal', {param})});	-- and set an error if not added
    				end
    			end
    		end
    	end
    
    	return name, etal;
    end
    
    
    --[[---------------------< N A M E _ I S _ N U M E R I C >----------------------
    
    Add maint cat when name parameter value does not contain letters.  Does not catch
    mixed alphanumeric names so |last=A. Green (1922-1987) does not get caught in the
    current version of this test but |first=(1888) is caught.
    
    returns nothing
    
    ]]
    
    local function name_is_numeric (name, list_name)
    	if utilities.is_set (name) then
    		if mw.ustring.match (name, '^[%A]+$') then								-- when name does not contain any letters
    			utilities.set_message ('maint_numeric_names', cfg.special_case_translation [list_name]);	-- add a maint cat for this template
    		end
    	end
    end
    
    
    --[[-------------------< N A M E _ H A S _ E D _ M A R K U P >------------------
    
    Evaluates the content of author and editor parameters for extraneous editor annotations:
    ed, ed., eds, (Ed.), etc. These annotations do not belong in author parameters and
    are redundant in editor parameters.  If found, the function adds the editor markup
    maintenance category.
    
    returns nothing
    
    ]]
    
    local function name_has_ed_markup (name, list_name)
    	local patterns = cfg.editor_markup_patterns;								-- get patterns from configuration
    
    	if utilities.is_set (name) then
    		for _, pattern in ipairs (patterns) do									-- spin through patterns table and
    			if name:match (pattern) then
    				utilities.set_message ('maint_extra_text_names', cfg.special_case_translation [list_name]);	-- add a maint cat for this template
    				break;
    			end
    		end
    	end
    end
    
    
    --[[-----------------< N A M E _ H A S _ M U L T _ N A M E S >------------------
    
    Evaluates the content of last/surname (authors etc.) parameters for multiple names.
    Multiple names are indicated if there is more than one comma or any "unescaped"
    semicolons. Escaped semicolons are ones used as part of selected HTML entities.
    If the condition is met, the function adds the multiple name maintenance category.
    
    returns nothing
    
    ]]
    
    local function name_has_mult_names (name, list_name)
    	local _, commas, semicolons, nbsps;
    	if utilities.is_set (name) then
    		_, commas = name:gsub (',', '');										-- count the number of commas
    		_, semicolons = name:gsub (';', '');									-- count the number of semicolons
    		-- nbsps probably should be its own separate count rather than merged in
    		-- some way with semicolons because Lua patterns do not support the
    		-- grouping operator that regex does, which means there is no way to add
    		-- more entities to escape except by adding more counts with the new
    		-- entities
    		_, nbsps = name:gsub ('&nbsp;','');										-- count nbsps
    		
    		-- There is exactly 1 semicolon per &nbsp; entity, so subtract nbsps
    		-- from semicolons to 'escape' them. If additional entities are added,
    		-- they also can be subtracted.
    		if 1 < commas or 0 < (semicolons - nbsps) then
    			utilities.set_message ('maint_mult_names', cfg.special_case_translation [list_name]);	-- add a maint message
    		end
    	end
    end
    
    
    --[[------------------------< N A M E _ C H E C K S >---------------------------
    
    This function calls various name checking functions used to validate the content
    of the various name-holding parameters.
    
    ]]
    
    local function name_checks (last, first, list_name)
    	local accept_name;
    
    	if utilities.is_set (last) then
    		last, accept_name = utilities.has_accept_as_written (last);				-- remove accept-this-as-written markup when it wraps all of <last>
    		
    		if not accept_name then													-- <last> not wrapped in accept-as-written markup
    			name_has_mult_names (last, list_name);								-- check for multiple names in the parameter (last only)
    			name_has_ed_markup (last, list_name);								-- check for extraneous 'editor' annotation
    			name_is_numeric (last, list_name);									-- check for names that are composed of digits and punctuation
    		end
    	end
    
    	if utilities.is_set (first) then
    		first, accept_name = utilities.has_accept_as_written (first);			-- remove accept-this-as-written markup when it wraps all of <first>
    
    		if not accept_name then													-- <first> not wrapped in accept-as-written markup
    			name_has_ed_markup (first, list_name);								-- check for extraneous 'editor' annotation
    			name_is_numeric (first, list_name);									-- check for names that are composed of digits and punctuation
    		end
    	end
    
    	return last, first;															-- done
    end
    
    
    --[[----------------------< E X T R A C T _ N A M E S >-------------------------
    Gets name list from the input arguments
    
    Searches through args in sequential order to find |lastn= and |firstn= parameters
    (or their aliases), and their matching link and mask parameters. Stops searching
    when both |lastn= and |firstn= are not found in args after two sequential attempts:
    found |last1=, |last2=, and |last3= but doesn't find |last4= and |last5= then the
    search is done.
    
    This function emits an error message when there is a |firstn= without a matching
    |lastn=.  When there are 'holes' in the list of last names, |last1= and |last3=
    are present but |last2= is missing, an error message is emitted. |lastn= is not
    required to have a matching |firstn=.
    
    When an author or editor parameter contains some form of 'et al.', the 'et al.'
    is stripped from the parameter and a flag (etal) returned that will cause list_people()
    to add the static 'et al.' text from Module:Citation/CS1/Configuration.  This keeps
    'et al.' out of the template's metadata.  When this occurs, an error is emitted.
    
    ]]
    
    local function extract_names(args, list_name)
    	local names = {};															-- table of names
    	local last;																	-- individual name components
    	local first;
    	local link;
    	local mask;
    	local i = 1;																-- loop counter/indexer
    	local n = 1;																-- output table indexer
    	local count = 0;															-- used to count the number of times we haven't found a |last= (or alias for authors, |editor-last or alias for editors)
    	local etal = false;															-- return value set to true when we find some form of et al. in an author parameter
    
    	local last_alias, first_alias, link_alias;									-- selected parameter aliases used in error messaging
    	while true do
    		last, last_alias = utilities.select_one ( args, cfg.aliases[list_name .. '-Last'], 'err_redundant_parameters', i );		-- search through args for name components beginning at 1
    		first, first_alias = utilities.select_one ( args, cfg.aliases[list_name .. '-First'], 'err_redundant_parameters', i );
    		link, link_alias = utilities.select_one ( args, cfg.aliases[list_name .. '-Link'], 'err_redundant_parameters', i );
    		mask = utilities.select_one ( args, cfg.aliases[list_name .. '-Mask'], 'err_redundant_parameters', i );
    
    		last, etal = name_has_etal (last, etal, false, last_alias);				-- find and remove variations on et al.
    		first, etal = name_has_etal (first, etal, false, first_alias);			-- find and remove variations on et al.
    		last, first = name_checks (last, first, list_name);						-- multiple names, extraneous annotation, etc. checks
    		
    		if first and not last then												-- if there is a firstn without a matching lastn
    			local alias = first_alias:find ('given', 1, true) and 'given' or 'first';	-- get first or given form of the alias
    			table.insert (z.message_tail, { utilities.set_message ( 'err_first_missing_last', {
    				first_alias,													-- param name of alias missing its mate
    				first_alias:gsub (alias, {['first'] = 'last', ['given'] = 'surname'}),	-- make param name appropriate to the alias form
    				}, true ) } );													-- add this error message
    		elseif not first and not last then										-- if both firstn and lastn aren't found, are we done?
    			count = count + 1;													-- number of times we haven't found last and first
    			if 2 <= count then													-- two missing names and we give up
    				break;															-- normal exit or there is a two-name hole in the list; can't tell which
    			end
    		else																	-- we have last with or without a first
    			local result;
    			link = link_title_ok (link, link_alias, last, last_alias);			-- check for improper wiki-markup
    			if first then
    				link = link_title_ok (link, link_alias, first, first_alias);	-- check for improper wiki-markup
    			end
    
    			names[n] = {last = last, first = first, link = link, mask = mask, corporate = false};	-- add this name to our names list (corporate for |vauthors= only)
    			n = n + 1;															-- point to next location in the names table
    			if 1 == count then													-- if the previous name was missing
    				table.insert( z.message_tail, { utilities.set_message ( 'err_missing_name', {list_name:match ("(%w+)List"):lower(), i - 1}, true ) } );	-- add this error message
    			end
    			count = 0;															-- reset the counter, we're looking for two consecutive missing names
    		end
    		i = i + 1;																-- point to next args location
    	end
    	
    	return names, etal;															-- all done, return our list of names and the etal flag
    end
    
    
    --[[---------------------< G E T _ I S O 6 3 9 _ C O D E >----------------------
    
    Validates language names provided in |language= parameter if not an ISO639-1 or 639-2 code.
    
    Returns the language name and associated two- or three-character code.  Because
    case of the source may be incorrect or different from the case that WikiMedia uses,
    the name comparisons are done in lower case and when a match is found, the Wikimedia
    version (assumed to be correct) is returned along with the code.  When there is no
    match, we return the original language name string.
    
    mw.language.fetchLanguageNames(<local wiki language>, 'all') returns a list of
    languages that in some cases may include extensions. For example, code 'cbk-zam'
    and its associated name 'Chavacano de Zamboanga' (MediaWiki does not support
    code 'cbk' or name 'Chavacano'.  Most (all?) of these languages are not used a
    'language' codes per se, rather they are used as sub-domain names: cbk-zam.wikipedia.org.
    A list of language names and codes supported by fetchLanguageNames() can be found
    at Template:Citation Style documentation/language/doc
    
    Names that are included in the list will be found if that name is provided in the
    |language= parameter.  For example, if |language=Chavacano de Zamboanga, that name
    will be found with the associated code 'cbk-zam'.  When names are found and the
    associated code is not two or three characters, this function returns only the
    WikiMedia language name.
    
    Some language names have multiple entries under different codes:
    	Aromanian has code rup and code roa-rup
    When this occurs, this function returns the language name and the 2- or 3-character code
    
    Adapted from code taken from Module:Check ISO 639-1.
    
    ]]
    
    local function get_iso639_code (lang, this_wiki_code)
    	if cfg.lang_name_remap[lang:lower()] then									-- if there is a remapped name (because MediaWiki uses something that we don't think is correct)
    		return cfg.lang_name_remap[lang:lower()][1], cfg.lang_name_remap[lang:lower()][2];	-- for this language 'name', return a possibly new name and appropriate code
    	end
    
    	local ietf_code;															-- because some languages have both IETF-like codes and ISO 639-like codes
    	local ietf_name;
    	
    	local langlc = mw.ustring.lower (lang);										-- lower-case version for comparisons
    
    	for code, name in pairs (cfg.languages) do									-- scan the list to see if we can find our language
    		if langlc == mw.ustring.lower (name) then
    			if 2 == #code or 3 == #code then									-- two- or three-character codes only; IETF extensions not supported
    				return name, code;												-- so return the name and the code
    			end
    			ietf_code = code;													-- remember that we found an IETF-like code and save its name
    			ietf_name = name;													-- but keep looking for a 2- or 3-char code
    		end
    	end
    																				-- didn't find name with 2- or 3-char code; if IETF-like code found return
    	return ietf_code and ietf_name or lang;										-- associated name; return original language text else
    end
    
    
    --[[-------------------< L A N G U A G E _ P A R A M E T E R >------------------
    
    Gets language name from a provided two- or three-character ISO 639 code.  If a code
    is recognized by MediaWiki, use the returned name; if not, then use the value that
    was provided with the language parameter.
    
    When |language= contains a recognized language (either code or name), the page is
    assigned to the category for that code: Category:Norwegian-language sources (no).
    For valid three-character code languages, the page is assigned to the single category
    for '639-2' codes: Category:CS1 ISO 639-2 language sources.
    
    Languages that are the same as the local wiki are not categorized.  MediaWiki does
    not recognize three-character equivalents of two-character codes: code 'ar' is
    recognized but code 'ara' is not.
    
    This function supports multiple languages in the form |language=nb, French, th
    where the language names or codes are separated from each other by commas with
    optional space characters.
    
    ]]
    
    local function language_parameter (lang)
    	local code;																	-- the two- or three-character language code
    	local name;																	-- the language name
    	local language_list = {};													-- table of language names to be rendered
    	local names_table = {};														-- table made from the value assigned to |language=
    
    	local this_wiki_name = mw.language.fetchLanguageName (cfg.this_wiki_code, cfg.this_wiki_code);	-- get this wiki's language name
    
    	names_table = mw.text.split (lang, '%s*,%s*');								-- names should be a comma separated list
    
    	for _, lang in ipairs (names_table) do										-- reuse lang
    		name = cfg.lang_code_remap[lang:lower()];								-- first see if this is a code that is not supported by MediaWiki but is in remap
    
    		if name then															-- there was a remapped code so
    			if not lang:match ('^%a%a%a?%-x%-%a+$') then						-- if not a private IETF tag
    				lang = lang:gsub ('^(%a%a%a?)%-.*', '%1');						-- strip IETF tags from code
    			end
    		else
    			lang = lang:gsub ('^(%a%a%a?)%-.*', '%1');							-- strip any IETF-like tags from code
    			if 2 == lang:len() or 3 == lang:len() then							-- if two-or three-character code
    				name = mw.language.fetchLanguageName (lang:lower(), cfg.this_wiki_code);	-- get language name if |language= is a proper code
    			end
    		end
    
    		if utilities.is_set (name) then											-- if |language= specified a valid code
    			code = lang:lower();												-- save it
    		else
    			name, code = get_iso639_code (lang, cfg.this_wiki_code);			-- attempt to get code from name (assign name here so that we are sure of proper capitalization)
    		end
    	
    		if utilities.is_set (code) then											-- only 2- or 3-character codes
    			name = cfg.lang_code_remap[code] or name;							-- override wikimedia when they misuse language codes/names
    
    			if cfg.this_wiki_code ~= code then									-- when the language is not the same as this wiki's language
    				if 2 == code:len() then											-- and is a two-character code
    					utilities.add_prop_cat ('foreign_lang_source' .. code, {name, code});	-- categorize it; code appended to allow for multiple language categorization
    				else															-- or is a recognized language (but has a three-character code)
    					utilities.add_prop_cat ('foreign_lang_source_2' .. code, {code});		-- categorize it differently TODO: support multiple three-character code categories per cs1|2 template
    				end
    			elseif cfg.local_lang_cat_enable then								-- when the language and this wiki's language are the same and categorization is enabled
    				utilities.add_prop_cat ('local_lang_source', {name, code});		-- categorize it
    			end
    		else
    			utilities.set_message ('maint_unknown_lang');						-- add maint category if not already added
    		end
    		
    		table.insert (language_list, name);
    		name = '';																-- so we can reuse it
    	end
     
    	name = utilities.make_sep_list (#language_list, language_list);
    
    	if this_wiki_name == name then
    		return '';																-- if one language and that language is this wiki's return an empty string (no annotation)
    	end
    	return (" " .. wrap_msg ('language', name));								-- otherwise wrap with '(in ...)'
    	--[[ TODO: should only return blank or name rather than full list
    	so we can clean up the bunched parenthetical elements Language, Type, Format
    	]]
    end
    
    --[[-----------------------< S E T _ C S _ S T Y L E >--------------------------
    Gets the default CS style configuration for the given mode.
    Returns default separator and either postscript as passed in or the default.
    In CS1, the default postscript and separator are '.'.
    In CS2, the default postscript is the empty string and the default separator is ','.
    ]]
    local function set_cs_style (postscript, mode)
    	if utilities.is_set(postscript) then
    		-- emit a maintenance message if user postscript is the default cs1 postscript
    		-- we catch the opposite case for cs2 in set_style
    		if mode == 'cs1' and postscript == cfg.presentation['ps_' .. mode] then
    			utilities.set_message ('maint_postscript');
    		end
    	else
    		postscript = cfg.presentation['ps_' .. mode];
    	end
    	return cfg.presentation['sep_' .. mode], postscript;
    end
    
    --[[--------------------------< S E T _ S T Y L E >-----------------------------
    Sets the separator and postscript styles. Checks the |mode= first and the
    #invoke CitationClass second. Removes the postscript if postscript == none.
    ]]
    local function set_style (mode, postscript, cite_class)
    	local sep;
    	if 'cs2' == mode then
    		sep, postscript = set_cs_style (postscript, 'cs2');
    	elseif 'cs1' == mode then
    		sep, postscript = set_cs_style (postscript, 'cs1');
    	elseif 'citation' == cite_class	then
    		sep, postscript = set_cs_style (postscript, 'cs2');
    	else
    		sep, postscript = set_cs_style (postscript, 'cs1');
    	end
    
    	if cfg.keywords_xlate[postscript:lower()] == 'none' then
    		-- emit a maintenance message if user postscript is the default cs2 postscript
    		-- we catch the opposite case for cs1 in set_cs_style
    		if 'cs2' == mode or 'citation' == cite_class then
    			utilities.set_message ('maint_postscript');
    		end
    		postscript = '';
    	end
    	
    	return sep, postscript
    end
    
    --[=[-------------------------< I S _ P D F >-----------------------------------
    
    Determines if a URL has the file extension that is one of the PDF file extensions
    used by [[MediaWiki:Common.css]] when applying the PDF icon to external links.
    
    returns true if file extension is one of the recognized extensions, else false
    
    ]=]
    
    local function is_pdf (url)
    	return url:match ('%.pdf$') or url:match ('%.PDF$') or
    		url:match ('%.pdf[%?#]') or url:match ('%.PDF[%?#]') or
    		url:match ('%.PDF&#035') or url:match ('%.pdf&#035');
    end
    
    
    --[[--------------------------< S T Y L E _ F O R M A T >-----------------------
    
    Applies CSS style to |format=, |chapter-format=, etc.  Also emits an error message
    if the format parameter does not have a matching URL parameter.  If the format parameter
    is not set and the URL contains a file extension that is recognized as a PDF document
    by MediaWiki's commons.css, this code will set the format parameter to (PDF) with
    the appropriate styling.
    
    ]]
    
    local function style_format (format, url, fmt_param, url_param)
    	if utilities.is_set (format) then
    		format = utilities.wrap_style ('format', format);						-- add leading space, parentheses, resize
    		if not utilities.is_set (url) then
    			format = format .. ' ' .. utilities.set_message ( 'err_format_missing_url', {fmt_param, url_param} );	-- add an error message
    		end
    	elseif is_pdf (url) then													-- format is not set so if URL is a PDF file then
    		format = utilities.wrap_style ('format', 'PDF');						-- set format to PDF
    	else
    		format = '';															-- empty string for concatenation
    	end
    	return format;
    end
    
    
    --[[---------------------< G E T _ D I S P L A Y _ N A M E S >------------------
    
    Returns a number that defines the number of names displayed for author and editor
    name lists and a Boolean flag to indicate when et al. should be appended to the name list.
    
    When the value assigned to |display-xxxxors= is a number greater than or equal to zero,
    return the number and the previous state of the 'etal' flag (false by default
    but may have been set to true if the name list contains some variant of the text 'et al.').
    
    When the value assigned to |display-xxxxors= is the keyword 'etal', return a number
    that is one greater than the number of authors in the list and set the 'etal' flag true.
    This will cause the list_people() to display all of the names in the name list followed by 'et al.'
    
    In all other cases, returns nil and the previous state of the 'etal' flag.
    
    inputs:
    	max: A['DisplayAuthors'] or A['DisplayEditors']; a number or some flavor of etal
    	count: #a or #e
    	list_name: 'authors' or 'editors'
    	etal: author_etal or editor_etal
    
    ]]
    
    local function get_display_names (max, count, list_name, etal, param)
    	if utilities.is_set (max) then
    		if 'etal' == max:lower():gsub("[ '%.]", '') then						-- the :gsub() portion makes 'etal' from a variety of 'et al.' spellings and stylings
    			max = count + 1;													-- number of authors + 1 so display all author name plus et al.
    			etal = true;														-- overrides value set by extract_names()
    		elseif max:match ('^%d+$') then											-- if is a string of numbers
    			max = tonumber (max);												-- make it a number
    			if max >= count then												-- if |display-xxxxors= value greater than or equal to number of authors/editors
    				table.insert( z.message_tail, {utilities.set_message ('err_disp_name', {param, max}, true)});	-- add error message
    				max = nil;
    			end
    		else																	-- not a valid keyword or number
    			table.insert( z.message_tail, {utilities.set_message ('err_disp_name', {param, max}, true)});		-- add error message
    			max = nil;															-- unset; as if |display-xxxxors= had not been set
    		end
    	end
    	
    	return max, etal;
    end
    
    
    --[[----------< E X T R A _ T E X T _ I N _ P A G E _ C H E C K >---------------
    
    Adds error if |page=, |pages=, |quote-page=, |quote-pages= has what appears to be
    some form of p. or pp. abbreviation in the first characters of the parameter content.
    
    check page for extraneous p, p., pp, pp., pg, pg. at start of parameter value:
    	good pattern: '^P[^%.P%l]' matches when page begins PX or P# but not Px
    		      where x and X are letters and # is a digit
    	bad pattern:  '^[Pp][PpGg]' matches when page begins pp, pP, Pp, PP, pg, pG, Pg, PG
    
    ]]
    
    local function extra_text_in_page_check (val, name)
    	if not val:match (cfg.vol_iss_pg_patterns.good_ppattern) then
    		for _, pattern in ipairs (cfg.vol_iss_pg_patterns.bad_ppatterns) do		-- spin through the selected sequence table of patterns
    			if val:match (pattern) then											-- when a match, error so
    				table.insert (z.message_tail, {utilities.set_message ('err_extra_text_pages', {name}, true)}); -- add error message
    				return;															-- and done
    			end
    		end
    	end		
    end
    
    
    --[[--------------------------< E X T R A _ T E X T _ I N _ V O L _ I S S _ C H E C K >------------------------
    
    Adds error if |volume= or |issue= has what appears to be some form of redundant 'type' indicator.
    
    For |volume=:
    	'V.', or 'Vol.' (with or without the dot) abbreviations or 'Volume' in the first characters of the parameter
    	content (all case insensitive). 'V' and 'v' (without the dot) are presumed to be roman numerals so
    	are allowed.
    
    For |issue=:
    	'No.', 'I.', 'Iss.' (with or without the dot) abbreviations, or 'Issue' in the first characters of the
    	parameter content (all case insensitive).
    	
    Single character values ('v', 'i', 'n') allowed when not followed by separator character ('.', ':', '=', or
    whitespace character) – param values are trimmed of whitespace by MediaWiki before delivered to the module.
    	
    <val> is |volume= or |issue= parameter value
    <name> is |volume= or |issue= parameter name for error message
    <selector> is 'v' for |volume=, 'i' for |issue=
    
    sets error message on failure; returns nothing
    
    ]]
    
    local function extra_text_in_vol_iss_check (val, name, selector)
    	if not utilities.is_set (val) then
    		return;
    	end
    	
    	local patterns = 'v' == selector and cfg.vol_iss_pg_patterns.vpatterns or cfg.vol_iss_pg_patterns.ipatterns;
    
    	local handler = 'v' == selector and 'err_extra_text_volume' or 'err_extra_text_issue';
    	val = val:lower();															-- force parameter value to lower case
    	for _, pattern in ipairs (patterns) do										-- spin through the selected sequence table of patterns
    		if val:match (pattern) then												-- when a match, error so
    			table.insert (z.message_tail, {utilities.set_message (handler, {name}, true)}); -- add error message
    			return;																-- and done
    		end
    	end
    end
    
    
    --[=[-------------------------< G E T _ V _ N A M E _ T A B L E >----------------------------------------------
    
    split apart a |vauthors= or |veditors= parameter.  This function allows for corporate names, wrapped in doubled
    parentheses to also have commas; in the old version of the code, the doubled parentheses were included in the
    rendered citation and in the metadata.  Individual author names may be wikilinked
    
    	|vauthors=Jones AB, [[E. B. White|White EB]], ((Black, Brown, and Co.))
    
    ]=]
    
    local function get_v_name_table (vparam, output_table, output_link_table)
    	local name_table = mw.text.split(vparam, "%s*,%s*");						-- names are separated by commas
    	local wl_type, label, link;													-- wl_type not used here; just a placeholder
    	
    	local i = 1;
    	
    	while name_table[i] do
    		if name_table[i]:match ('^%(%(.*[^%)][^%)]$') then						-- first segment of corporate with one or more commas; this segment has the opening doubled parentheses
    			local name = name_table[i];
    			i = i + 1;															-- bump indexer to next segment
    			while name_table[i] do
    				name = name .. ', ' .. name_table[i];							-- concatenate with previous segments
    				if name_table[i]:match ('^.*%)%)$') then						-- if this table member has the closing doubled parentheses
    					break;														-- and done reassembling so
    				end
    				i = i + 1;														-- bump indexer
    			end
    			table.insert (output_table, name);									-- and add corporate name to the output table
    			table.insert (output_link_table, '');								-- no wikilink
    		else
    			wl_type, label, link = utilities.is_wikilink (name_table[i]);		-- wl_type is: 0, no wl (text in label variable); 1, [[D]]; 2, [[L|D]]
    			table.insert (output_table, label);									-- add this name
    			if 1 == wl_type then
    				table.insert (output_link_table, label);						-- simple wikilink [[D]]
    			else
    				table.insert (output_link_table, link);							-- no wikilink or [[L|D]]; add this link if there is one, else empty string
    			end
    		end
    		i = i + 1;
    	end	
    	return output_table;
    end
    
    
    --[[--------------------------< P A R S E _ V A U T H O R S _ V E D I T O R S >--------------------------------
    
    This function extracts author / editor names from |vauthors= or |veditors= and finds matching |xxxxor-maskn= and
    |xxxxor-linkn= in args.  It then returns a table of assembled names just as extract_names() does.
    
    Author / editor names in |vauthors= or |veditors= must be in Vancouver system style. Corporate or institutional names
    may sometimes be required and because such names will often fail the is_good_vanc_name() and other format compliance
    tests, are wrapped in doubled parentheses ((corporate name)) to suppress the format tests.
    
    Supports generational suffixes Jr, 2nd, 3rd, 4th–6th.
    
    This function sets the Vancouver error when a required comma is missing and when there is a space between an author's initials.
    
    ]]
    
    local function parse_vauthors_veditors (args, vparam, list_name)
    	local names = {};															-- table of names assembled from |vauthors=, |author-maskn=, |author-linkn=
    	local v_name_table = {};
    	local v_link_table = {};													-- when name is wikilinked, targets go in this table
    	local etal = false;															-- return value set to true when we find some form of et al. vauthors parameter
    	local last, first, link, mask, suffix;
    	local corporate = false;
    
    	vparam, etal = name_has_etal (vparam, etal, true);							-- find and remove variations on et al. do not categorize (do it here because et al. might have a period)
    	v_name_table = get_v_name_table (vparam, v_name_table, v_link_table);		-- names are separated by commas
    
    	for i, v_name in ipairs(v_name_table) do
    		first = '';																-- set to empty string for concatenation and because it may have been set for previous author/editor
    		local accept_name;
    		v_name, accept_name = utilities.has_accept_as_written (v_name);			-- remove accept-this-as-written markup when it wraps all of <v_name>
    
    		if accept_name then
    			last = v_name;
    			corporate = true;													-- flag used in list_people()
    		elseif string.find(v_name, "%s") then
    			if v_name:find('[;%.]') then										-- look for commonly occurring punctuation characters; 
    				add_vanc_error (cfg.err_msg_supl.punctuation, i);
    			end
    			local lastfirstTable = {}
    			lastfirstTable = mw.text.split(v_name, "%s+")
    			first = table.remove(lastfirstTable);								-- removes and returns value of last element in table which should be initials or generational suffix
    
    			if not mw.ustring.match (first, '^%u+$') then						-- mw.ustring here so that later we will catch non-Latin characters
    				suffix = first;													-- not initials so assume that whatever we got is a generational suffix
    				first = table.remove(lastfirstTable);							-- get what should be the initials from the table
    			end
    			last = table.concat(lastfirstTable, ' ')							-- returns a string that is the concatenation of all other names that are not initials and generational suffix
    			if not utilities.is_set (last) then
    				first = '';														-- unset
    				last = v_name;													-- last empty because something wrong with first
    				add_vanc_error (cfg.err_msg_supl.name, i);
    			end
    			if mw.ustring.match (last, '%a+%s+%u+%s+%a+') then
    				add_vanc_error (cfg.err_msg_supl['missing comma'], i);			-- matches last II last; the case when a comma is missing
    			end
    			if mw.ustring.match (v_name, ' %u %u$') then						-- this test is in the wrong place TODO: move or replace with a more appropriate test
    				add_vanc_error (cfg.err_msg_supl.initials, i);					-- matches a space between two initials
    			end
    		else
    			last = v_name;														-- last name or single corporate name?  Doesn't support multiword corporate names? do we need this?
    		end
    		
    		if utilities.is_set (first) then
    			if not mw.ustring.match (first, "^%u?%u$") then						-- first shall contain one or two upper-case letters, nothing else
    				add_vanc_error (cfg.err_msg_supl.initials, i);					-- too many initials; mixed case initials (which may be ok Romanization); hyphenated initials
    			end
    			is_good_vanc_name (last, first, suffix, i);							-- check first and last before restoring the suffix which may have a non-Latin digit
    			if utilities.is_set (suffix) then
    				first = first .. ' ' .. suffix;									-- if there was a suffix concatenate with the initials
    				suffix = '';													-- unset so we don't add this suffix to all subsequent names
    			end
    		else
    			if not corporate then
    				is_good_vanc_name (last, '', nil, i);
    			end
    		end
    
    		link = utilities.select_one ( args, cfg.aliases[list_name .. '-Link'], 'err_redundant_parameters', i ) or v_link_table[i];
    		mask = utilities.select_one ( args, cfg.aliases[list_name .. '-Mask'], 'err_redundant_parameters', i );
    		names[i] = {last = last, first = first, link = link, mask = mask, corporate = corporate};		-- add this assembled name to our names list
    	end
    	return names, etal;															-- all done, return our list of names
    end
    
    
    --[[--------------------------< S E L E C T _ A U T H O R _ E D I T O R _ S O U R C E >------------------------
    
    Select one of |authors=, |authorn= / |lastn / firstn=, or |vauthors= as the source of the author name list or
    select one of |editorn= / editor-lastn= / |editor-firstn= or |veditors= as the source of the editor name list.
    
    Only one of these appropriate three will be used.  The hierarchy is: |authorn= (and aliases) highest and |authors= lowest;
    |editorn= (and aliases) highest and |veditors= lowest (support for |editors= withdrawn)
    
    When looking for |authorn= / |editorn= parameters, test |xxxxor1= and |xxxxor2= (and all of their aliases); stops after the second
    test which mimicks the test used in extract_names() when looking for a hole in the author name list.  There may be a better
    way to do this, I just haven't discovered what that way is.
    
    Emits an error message when more than one xxxxor name source is provided.
    
    In this function, vxxxxors = vauthors or veditors; xxxxors = authors as appropriate.
    
    ]]
    
    local function select_author_editor_source (vxxxxors, xxxxors, args, list_name)
    	local lastfirst = false;
    	if utilities.select_one ( args, cfg.aliases[list_name .. '-Last'], 'none', 1 ) or		-- do this twice in case we have a |first1= without a |last1=; this ...
    		utilities.select_one ( args, cfg.aliases[list_name .. '-First'], 'none', 1 ) or		-- ... also catches the case where |first= is used with |vauthors=
    		utilities.select_one ( args, cfg.aliases[list_name .. '-Last'], 'none', 2 ) or
    		utilities.select_one ( args, cfg.aliases[list_name .. '-First'], 'none', 2 ) then
    			lastfirst = true;
    	end
    
    	if (utilities.is_set (vxxxxors) and true == lastfirst) or					-- these are the three error conditions
    		(utilities.is_set (vxxxxors) and utilities.is_set (xxxxors)) or
    		(true == lastfirst and utilities.is_set (xxxxors)) then
    			local err_name;
    			if 'AuthorList' == list_name then									-- figure out which name should be used in error message
    				err_name = 'author';
    			else
    				err_name = 'editor';
    			end
    			table.insert( z.message_tail, { utilities.set_message ( 'err_redundant_parameters',
    				{err_name .. '-name-list parameters'}, true ) } );				-- add error message
    	end
    
    	if true == lastfirst then return 1 end;										-- return a number indicating which author name source to use
    	if utilities.is_set (vxxxxors) then return 2 end;
    	if utilities.is_set (xxxxors) then return 3 end;
    	return 1;																	-- no authors so return 1; this allows missing author name test to run in case there is a first without last 
    end
    
    
    --[[--------------------------< I S _ V A L I D _ P A R A M E T E R _ V A L U E >------------------------------
    
    This function is used to validate a parameter's assigned value for those parameters that have only a limited number
    of allowable values (yes, y, true, live, dead, etc.).  When the parameter value has not been assigned a value (missing
    or empty in the source template) the function returns the value specified by ret_val.  If the parameter value is one
    of the list of allowed values returns the translated value; else, emits an error message and returns the value
    specified by ret_val.
    
    ]]
    
    local function is_valid_parameter_value (value, name, possible, ret_val)
    	if not utilities.is_set (value) then
    		return ret_val;															-- an empty parameter is ok
    	elseif utilities.in_array (value, possible) then
    		return cfg.keywords_xlate[value];										-- return translation of parameter keyword
    	else
    		table.insert( z.message_tail, { utilities.set_message ( 'err_invalid_param_val', {name, value}, true ) } );	-- not an allowed value so add error message
    		return ret_val;
    	end
    end
    
    
    --[[--------------------------< T E R M I N A T E _ N A M E _ L I S T >----------------------------------------
    
    This function terminates a name list (author, contributor, editor) with a separator character (sepc) and a space
    when the last character is not a sepc character or when the last three characters are not sepc followed by two
    closing square brackets (close of a wikilink).  When either of these is true, the name_list is terminated with a
    single space character.
    
    ]]
    
    local function terminate_name_list (name_list, sepc)
    	if (string.sub (name_list, -3, -1) == sepc .. '. ') then					-- if already properly terminated
    		return name_list;														-- just return the name list
    	elseif (string.sub (name_list, -1, -1) == sepc) or (string.sub (name_list, -3, -1) == sepc .. ']]') then	-- if last name in list ends with sepc char
    		return name_list .. " ";												-- don't add another
    	else
    		return name_list .. sepc .. ' ';										-- otherwise terminate the name list
    	end
    end
    
    
    --[[-------------------------< F O R M A T _ V O L U M E _ I S S U E >----------------------------------------
    
    returns the concatenation of the formatted volume and issue parameters as a single string; or formatted volume
    or formatted issue, or an empty string if neither are set.
    
    ]]
    	
    local function format_volume_issue (volume, issue, cite_class, origin, sepc, lower)
    	if not utilities.is_set (volume) and not utilities.is_set (issue) then
    		return '';
    	end
    	
    	if 'magazine' == cite_class or (utilities.in_array (cite_class, {'citation', 'map'}) and 'magazine' == origin) then
    		if utilities.is_set (volume) and utilities.is_set (issue) then
    			return wrap_msg ('vol-no', {sepc, hyphen_to_dash (volume), issue}, lower);
    		elseif utilities.is_set (volume) then
    			return wrap_msg ('vol', {sepc, hyphen_to_dash (volume)}, lower);
    		else
    			return wrap_msg ('issue', {sepc, issue}, lower);
    		end
    	end
    
    	if 'podcast' == cite_class and utilities.is_set (issue) then
    		return wrap_msg ('issue', {sepc, issue}, lower);
    	end
    
    	local vol = '';																-- here for all cites except magazine
    		
    	if utilities.is_set (volume) then
    		if volume:match ('^[MDCLXVI]+$') or volume:match ('^%d+$') then			-- volume value is all digits or all uppercase Roman numerals
    			vol = utilities.substitute (cfg.presentation['vol-bold'], {sepc, volume});	-- render in bold face
    		elseif (4 < mw.ustring.len(volume)) then								-- not all digits or Roman numerals and longer than 4 characters
    			vol = utilities.substitute (cfg.messages['j-vol'], {sepc, hyphen_to_dash (volume)});	-- not bold
    			utilities.add_prop_cat ('long_vol');
    		else																	-- four or less characters
    			vol = utilities.substitute (cfg.presentation['vol-bold'], {sepc, hyphen_to_dash (volume)});	-- bold
    		end
    	end
    	if utilities.is_set (issue) then
    		return vol .. utilities.substitute (cfg.messages['j-issue'], issue);
    	end
    	return vol;
    end
    
    
    --[[-------------------------< F O R M A T _ P A G E S _ S H E E T S >-----------------------------------------
    
    adds static text to one of |page(s)= or |sheet(s)= values and returns it with all of the others set to empty strings.
    The return order is:
    	page, pages, sheet, sheets
    
    Singular has priority over plural when both are provided.
    
    ]]
    
    local function format_pages_sheets (page, pages, sheet, sheets, cite_class, origin, sepc, nopp, lower)
    	if 'map' == cite_class then													-- only cite map supports sheet(s) as in-source locators
    		if utilities.is_set (sheet) then
    			if 'journal' == origin then
    				return '', '', wrap_msg ('j-sheet', sheet, lower), '';
    			else
    				return '', '', wrap_msg ('sheet', {sepc, sheet}, lower), '';
    			end
    		elseif utilities.is_set (sheets) then
    			if 'journal' == origin then
    				return '', '', '', wrap_msg ('j-sheets', sheets, lower);
    			else
    				return '', '', '', wrap_msg ('sheets', {sepc, sheets}, lower);
    			end
    		end
    	end
    
    	local is_journal = 'journal' == cite_class or (utilities.in_array (cite_class, {'citation', 'map', 'interview'}) and 'journal' == origin);
    	
    	if utilities.is_set (page) then
    		if is_journal then
    			return utilities.substitute (cfg.messages['j-page(s)'], page), '', '', '';
    		elseif not nopp then
    			return utilities.substitute (cfg.messages['p-prefix'], {sepc, page}), '', '', '';
    		else
    			return utilities.substitute (cfg.messages['nopp'], {sepc, page}), '', '', '';
    		end
    	elseif utilities.is_set (pages) then
    		if is_journal then
    			return utilities.substitute (cfg.messages['j-page(s)'], pages), '', '', '';
    		elseif tonumber(pages) ~= nil and not nopp then							-- if pages is only digits, assume a single page number
    			return '', utilities.substitute (cfg.messages['p-prefix'], {sepc, pages}), '', '';
    		elseif not nopp then
    			return '', utilities.substitute (cfg.messages['pp-prefix'], {sepc, pages}), '', '';
    		else
    			return '', utilities.substitute (cfg.messages['nopp'], {sepc, pages}), '', '';
    		end
    	end
    	
    	return '', '', '', '';														-- return empty strings
    end
    
    
    --[[--------------------------< I N S O U R C E _ L O C _ G E T >----------------------------------------------
    
    returns one of the in-source locators: page, pages, or at. 
    
    If any of these are interwiki links to Wikisource, returns the label portion of the interwiki-link as plain text
    for use in COinS.  This COinS thing is done because here we convert an interwiki-link to an external link and
    add an icon span around that; get_coins_pages() doesn't know about the span.  TODO: should it?  
    
    TODO: add support for sheet and sheets?; streamline;
    
    TODO: make it so that this function returns only one of the three as the single in-source (the return value assigned
    to a new name)?
    
    ]]
    
    local function insource_loc_get (page, page_orig, pages, pages_orig, at)
    	local ws_url, ws_label, coins_pages, L;										-- for Wikisource interwiki-links; TODO: this corrupts page metadata (span remains in place after cleanup; fix there?)
    
    	if utilities.is_set (page) then
    		if utilities.is_set (pages) or utilities.is_set (at) then
    			pages = '';															-- unset the others
    			at = '';
    		end
    		extra_text_in_page_check (page, page_orig);								-- emit error message when |page= value begins with what looks like p., pp., etc.
    
    		ws_url, ws_label, L = wikisource_url_make (page);						-- make ws URL from |page= interwiki link; link portion L becomes tooltip label
    		if ws_url then
    			page = external_link (ws_url, ws_label .. '&nbsp;', 'ws link in page');	-- space char after label to move icon away from in-source text; TODO: a better way to do this?
    			page = utilities.substitute (cfg.presentation['interwiki-icon'], {cfg.presentation['class-wikisource'], L, page});
    			coins_pages = ws_label;
    		end
    	elseif utilities.is_set (pages) then
    		if utilities.is_set (at) then
    			at = '';															-- unset
    		end
    		extra_text_in_page_check (pages, pages_orig);							-- emit error message when |page= value begins with what looks like p., pp., etc.
    
    		ws_url, ws_label, L = wikisource_url_make (pages);						-- make ws URL from |pages= interwiki link; link portion L becomes tooltip label
    		if ws_url then
    			pages = external_link (ws_url, ws_label .. '&nbsp;', 'ws link in pages');	-- space char after label to move icon away from in-source text; TODO: a better way to do this?
    			pages = utilities.substitute (cfg.presentation['interwiki-icon'], {cfg.presentation['class-wikisource'], L, pages});
    			coins_pages = ws_label;
    		end
    	elseif utilities.is_set (at) then
    		ws_url, ws_label, L = wikisource_url_make (at);							-- make ws URL from |at= interwiki link; link portion L becomes tooltip label
    		if ws_url then
    			at = external_link (ws_url, ws_label .. '&nbsp;', 'ws link in at');	-- space char after label to move icon away from in-source text; TODO: a better way to do this?
    			at = utilities.substitute (cfg.presentation['interwiki-icon'], {cfg.presentation['class-wikisource'], L, at});
    			coins_pages = ws_label;
    		end
    	end
    	
    	return page, pages, at, coins_pages;
    end
    
    --[[--------------------------< I S _ U N I Q U E _ A R C H I V E _ U R L >------------------------------------
    
    add error message when |archive-url= value is same as |url= or chapter-url= (or alias...) value
    
    ]]
    
    local function is_unique_archive_url (archive, url, c_url, source, date)
    	if utilities.is_set (archive) then
    		if archive == url or archive == c_url then
    			table.insert (z.message_tail, {utilities.set_message ('err_bad_url', {utilities.wrap_style ('parameter', source)}, true)});	-- add error message
    			return '', '';														-- unset |archive-url= and |archive-date= because same as |url= or |chapter-url=
    		end
    	end
    
    	return archive, date;
    end
    
    
    --[=[-------------------------< A R C H I V E _ U R L _ C H E C K >--------------------------------------------
    
    Check archive.org URLs to make sure they at least look like they are pointing at valid archives and not to the 
    save snapshot URL or to calendar pages.  When the archive URL is 'https://web.archive.org/save/' (or http://...)
    archive.org saves a snapshot of the target page in the URL.  That is something that Wikipedia should not allow
    unwitting readers to do.
    
    When the archive.org URL does not have a complete timestamp, archive.org chooses a snapshot according to its own
    algorithm or provides a calendar 'search' result.  [[WP:ELNO]] discourages links to search results.
    
    This function looks at the value assigned to |archive-url= and returns empty strings for |archive-url= and
    |archive-date= and an error message when:
    	|archive-url= holds an archive.org save command URL
    	|archive-url= is an archive.org URL that does not have a complete timestamp (YYYYMMDDhhmmss 14 digits) in the
    		correct place
    otherwise returns |archive-url= and |archive-date=
    
    There are two mostly compatible archive.org URLs:
    	//web.archive.org/<timestamp>...		-- the old form
    	//web.archive.org/web/<timestamp>...	-- the new form
    
    The old form does not support or map to the new form when it contains a display flag.  There are four identified flags
    ('id_', 'js_', 'cs_', 'im_') but since archive.org ignores others following the same form (two letters and an underscore)
    we don't check for these specific flags but we do check the form.
    
    This function supports a preview mode.  When the article is rendered in preview mode, this function may return a modified
    archive URL:
    	for save command errors, return undated wildcard (/*/)
    	for timestamp errors when the timestamp has a wildcard, return the URL unmodified
    	for timestamp errors when the timestamp does not have a wildcard, return with timestamp limited to six digits plus wildcard (/yyyymm*/)
    
    ]=]
    
    local function archive_url_check (url, date)
    	local err_msg = '';															-- start with the error message empty
    	local path, timestamp, flag;												-- portions of the archive.org URL
    	
    	if (not url:match('//web%.archive%.org/')) and (not url:match('//liveweb%.archive%.org/')) then		-- also deprecated liveweb Wayback machine URL
    		return url, date;														-- not an archive.org archive, return ArchiveURL and ArchiveDate
    	end
    
    	if url:match('//web%.archive%.org/save/') then								-- if a save command URL, we don't want to allow saving of the target page 
    		err_msg = cfg.err_msg_supl.save;
    		url = url:gsub ('(//web%.archive%.org)/save/', '%1/*/', 1);				-- for preview mode: modify ArchiveURL
    	elseif url:match('//liveweb%.archive%.org/') then
    		err_msg = cfg.err_msg_supl.liveweb;
    	else
    		path, timestamp, flag = url:match('//web%.archive%.org/([^%d]*)(%d+)([^/]*)/');	-- split out some of the URL parts for evaluation
    		
    		if not utilities.is_set (timestamp) or 14 ~= timestamp:len() then		-- path and flag optional, must have 14-digit timestamp here
    			err_msg = cfg.err_msg_supl.timestamp;
    			if '*' ~= flag then
    				url=url:gsub ('(//web%.archive%.org/[^%d]*%d?%d?%d?%d?%d?%d?)[^/]*', '%1*', 1)	-- for preview, modify ts to be yearmo* max (0-6 digits plus splat)
    			end
    		elseif utilities.is_set (path) and 'web/' ~= path then					-- older archive URLs do not have the extra 'web/' path element
    			err_msg = cfg.err_msg_supl.path;
    		elseif utilities.is_set (flag) and not utilities.is_set (path) then		-- flag not allowed with the old form URL (without the 'web/' path element)
    			err_msg = cfg.err_msg_supl.flag;
    		elseif utilities.is_set (flag) and not flag:match ('%a%a_') then		-- flag if present must be two alpha characters and underscore (requires 'web/' path element)
    			err_msg = cfg.err_msg_supl.flag;
    		else
    			return url, date;													-- return ArchiveURL and ArchiveDate
    		end
    	end
    																				-- if here, something not right so
    	table.insert( z.message_tail, { utilities.set_message ( 'err_archive_url', {err_msg}, true ) } );	-- add error message and
    	if utilities.is_set (Frame:preprocess('{{REVISIONID}}')) then
    		return '', '';															-- return empty strings for ArchiveURL and ArchiveDate
    	else
    		return url, date;														-- preview mode so return ArchiveURL and ArchiveDate
    	end
    end
    
    
    --[[--------------------------< P L A C E _ C H E C K >--------------------------------------------------------
    
    check |place=, |publication-place=, |location= to see if these params include digits.  This function added because
    many editors misuse location to specify the in-source location (|page(s)= and |at= are supposed to do that)
    
    returns the original parameter value without modification; added maint cat when parameter value contains digits
    
    ]]
    
    local function place_check (param_val)
    	if not utilities.is_set (param_val) then									-- parameter empty or omitted
    		return param_val;														-- return that empty state
    	end
    	
    	if mw.ustring.find (param_val, '%d') then									-- not empty, are there digits in the parameter value
    		utilities.set_message ('maint_location');								-- yep, add maint cat
    	end
    	
    	return param_val;															-- and done
    end
    
    
    --[[--------------------------< I S _ G E N E R I C _ T I T L E >----------------------------------------------
    
    compares |title= value against list of known generic title patterns.  Returns true when pattern matches; nil else
    
    the k/v pairs in 'generic_titles' each contain two tables, one for English and one for another 'local' language
    Each of those tables contain another table that holds the string or pattern (whole title or title fragment) in
    index [1].  index [2] is a Boolean that tells string.find() or mw.ustring.find() to do plain-text search (true)
    or a pattern search (false).  The intent of all this complexity is to make these searches as fast as possible so
    that we don't run out of processing time on very large articles.
    
    ]]
    
    local function is_generic_title (title)
    	title = mw.ustring.lower(title);											-- switch title to lower case
    	for _, generic_title in ipairs (cfg.special_case_translation['generic_titles']) do 	-- spin through the list of known generic title fragments
    		if title:find (generic_title['en'][1], 1, generic_title['en'][2]) then
    			return true;														-- found English generic title so done
    		elseif generic_title['local'] then										-- to keep work load down, generic_title['local'] should be nil except when there is a local version of the generic title
    			if mw.ustring.find (title, generic_title['local'][1], 1, generic_title['local'][2]) then	-- mw.ustring() because might not be Latin script
    				return true;													-- found local generic title so done
    			end
    		end
    	end
    end
    
    
    --[[--------------------------< I S _ A R C H I V E D _ C O P Y >----------------------------------------------
    
    compares |title= to 'Archived copy' (placeholder added by bots that can't find proper title); if matches, return true; nil else
    
    ]]
    
    local function is_archived_copy (title)
    	title = mw.ustring.lower(title);											-- switch title to lower case
    	if title:find (cfg.special_case_translation.archived_copy.en) then			-- if title is 'Archived copy'
    		return true;
    	elseif cfg.special_case_translation.archived_copy['local'] then
    		if mw.ustring.find (title, cfg.special_case_translation.archived_copy['local']) then	-- mw.ustring() because might not be Latin script
    			return true;
    		end
    	end
    end
    
    
    --[[--------------------------< C I T A T I O N 0 >------------------------------------------------------------
    
    This is the main function doing the majority of the citation formatting.
    
    ]]
    
    local function citation0( config, args )
    	--[[ 
    	Load Input Parameters
    	The argument_wrapper facilitates the mapping of multiple aliases to single internal variable.
    	]]
    	local A = argument_wrapper ( args );
    	local i 
    
    	-- Pick out the relevant fields from the arguments.  Different citation templates
    	-- define different field names for the same underlying things.	
    
    	local author_etal;
    	local a	= {};																-- authors list from |lastn= / |firstn= pairs or |vauthors=
    	local Authors;
    	local NameListStyle = is_valid_parameter_value (A['NameListStyle'], A:ORIGIN('NameListStyle'), cfg.keywords_lists['name-list-style'], '');
    	local Collaboration = A['Collaboration'];
    
    	do																			-- to limit scope of selected
    		local selected = select_author_editor_source (A['Vauthors'], A['Authors'], args, 'AuthorList');
    		if 1 == selected then
    			a, author_etal = extract_names (args, 'AuthorList');				-- fetch author list from |authorn= / |lastn= / |firstn=, |author-linkn=, and |author-maskn=
    		elseif 2 == selected then
    			NameListStyle = 'vanc';												-- override whatever |name-list-style= might be
    			a, author_etal = parse_vauthors_veditors (args, args.vauthors, 'AuthorList');	-- fetch author list from |vauthors=, |author-linkn=, and |author-maskn=
    		elseif 3 == selected then
    			Authors = A['Authors'];												-- use content of |authors=
    			if 'authors' == A:ORIGIN('Authors') then							-- but add a maint cat if the parameter is |authors=
    				utilities.set_message ('maint_authors');						-- because use of this parameter is discouraged; what to do about the aliases is a TODO:
    			end
    		end
    		if utilities.is_set (Collaboration) then
    			author_etal = true;													-- so that |display-authors=etal not required
    		end
    	end
    
    	local editor_etal;
    	local e	= {};																-- editors list from |editor-lastn= / |editor-firstn= pairs or |veditors=
    
    	do																			-- to limit scope of selected
    		local selected = select_author_editor_source (A['Veditors'], nil, args, 'EditorList');	-- support for |editors= withdrawn
    		if 1 == selected then
    			e, editor_etal = extract_names (args, 'EditorList');				-- fetch editor list from |editorn= / |editor-lastn= / |editor-firstn=, |editor-linkn=, and |editor-maskn=
    		elseif 2 == selected then
    			NameListStyle = 'vanc';												-- override whatever |name-list-style= might be
    			e, editor_etal = parse_vauthors_veditors (args, args.veditors, 'EditorList');	-- fetch editor list from |veditors=, |editor-linkn=, and |editor-maskn=
    		end
    	end
    							
    	local Chapter = A['Chapter'];												-- done here so that we have access to |contribution= from |chapter= aliases
    	local Chapter_origin = A:ORIGIN ('Chapter');
    	local Contribution;															-- because contribution is required for contributor(s)
    		if 'contribution' == Chapter_origin then
    			Contribution = Chapter;												-- get the name of the contribution
    		end
    	local c = {};																-- contributors list from |contributor-lastn= / contributor-firstn= pairs
    	
    	if utilities.in_array (config.CitationClass, {"book", "citation"}) and not utilities.is_set (A['Periodical']) then	-- |contributor= and |contribution= only supported in book cites
    		c = extract_names (args, 'ContributorList');							-- fetch contributor list from |contributorn= / |contributor-lastn=, -firstn=, -linkn=, -maskn=
    		
    		if 0 < #c then
    			if not utilities.is_set (Contribution) then							-- |contributor= requires |contribution=
    				table.insert( z.message_tail, { utilities.set_message ( 'err_contributor_missing_required_param', 'contribution')});	-- add missing contribution error message
    				c = {};															-- blank the contributors' table; it is used as a flag later
    			end
    			if 0 == #a then														-- |contributor= requires |author=
    				table.insert( z.message_tail, { utilities.set_message ( 'err_contributor_missing_required_param', 'author')});	-- add missing author error message
    				c = {};															-- blank the contributors' table; it is used as a flag later
    			end
    		end
    	else																		-- if not a book cite
    		if utilities.select_one (args, cfg.aliases['ContributorList-Last'], 'err_redundant_parameters', 1 ) then	-- are there contributor name list parameters?
    			table.insert( z.message_tail, { utilities.set_message ( 'err_contributor_ignored')});	-- add contributor ignored error message
    		end
    		Contribution = nil;														-- unset
    	end
    
    	local Title = A['Title'];
    	local TitleLink = A['TitleLink'];
    
    	local auto_select = ''; -- default is auto
    	local accept_link;
    	TitleLink, accept_link = utilities.has_accept_as_written(TitleLink, true);	-- test for accept-this-as-written markup
    	if (not accept_link) and utilities.in_array (TitleLink, {'none', 'pmc', 'doi'}) then -- check for special keywords
    		auto_select = TitleLink;												-- remember selection for later
    		TitleLink = '';															-- treat as if |title-link= would have been empty
    	end
    
    	TitleLink = link_title_ok (TitleLink, A:ORIGIN ('TitleLink'), Title, 'title');	-- check for wiki-markup in |title-link= or wiki-markup in |title= when |title-link= is set
    
    	local Section = '';															-- {{cite map}} only; preset to empty string for concatenation if not used
    	if 'map' == config.CitationClass and 'section' == Chapter_origin then
    		Section = A['Chapter'];													-- get |section= from |chapter= alias list; |chapter= and the other aliases not supported in {{cite map}}
    		Chapter = '';															-- unset for now; will be reset later from |map= if present
    	end
    
    	local Periodical = A['Periodical'];
    	local Periodical_origin = '';
    	if utilities.is_set (Periodical) then
    		Periodical_origin = A:ORIGIN('Periodical');								-- get the name of the periodical parameter
    		local i;
    		Periodical, i = utilities.strip_apostrophe_markup (Periodical);			-- strip apostrophe markup so that metadata isn't contaminated 
    		if i then																-- non-zero when markup was stripped so emit an error message
    			table.insert( z.message_tail, {utilities.set_message ('err_apostrophe_markup', {Periodical_origin}, true)});
    		end
    	end
    
    	if 'mailinglist' == config.CitationClass then								-- special case for {{cite mailing list}}
    		if utilities.is_set (Periodical) and utilities.is_set (A ['MailingList']) then	-- both set emit an error
    			table.insert( z.message_tail, {utilities.set_message ('err_redundant_parameters', {utilities.wrap_style ('parameter', Periodical_origin) .. ' and ' .. utilities.wrap_style ('parameter', 'mailinglist')}, true )});
    		end
    
    		Periodical = A ['MailingList'];											-- error or no, set Periodical to |mailinglist= value because this template is {{cite mailing list}}
    		Periodical_origin = A:ORIGIN('MailingList');
    	end
    
    	local ScriptPeriodical = A['ScriptPeriodical'];
    
    	-- web and news not tested for now because of 
    	-- Wikipedia:Administrators%27_noticeboard#Is_there_a_semi-automated_tool_that_could_fix_these_annoying_"Cite_Web"_errors?
    	if not (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical)) then	-- 'periodical' templates require periodical parameter
    	--	local p = {['journal'] = 'journal', ['magazine'] = 'magazine', ['news'] = 'newspaper', ['web'] = 'website'};	-- for error message
    		local p = {['journal'] = 'journal', ['magazine'] = 'magazine'};			-- for error message
    		if p[config.CitationClass]  then
    			table.insert( z.message_tail, {utilities.set_message ('err_missing_periodical', {config.CitationClass, p[config.CitationClass]}, true)});
    		end
    	end
    	
    	local Volume;
    	local ScriptPeriodical_origin = A:ORIGIN('ScriptPeriodical');
    	if 'citation' == config.CitationClass then
    		if utilities.is_set (Periodical) then
    			if not utilities.in_array (Periodical_origin, {'website', 'mailinglist'}) then	-- {{citation}} does not render volume for these 'periodicals'
    				Volume = A['Volume'];											-- but does for all other 'periodicals'
    			end
    		elseif utilities.is_set (ScriptPeriodical) then
    			if 'script-website' ~= ScriptPeriodical_origin then					-- {{citation}} does not render volume for |script-website=
    				Volume = A['Volume'];											-- but does for all other 'periodicals'
    			end
    		else
    			Volume = A['Volume'];												-- and does for non-'periodical' cites
    		end
    	elseif utilities.in_array (config.CitationClass, cfg.templates_using_volume) then	-- render |volume= for cs1 according to the configuration settings
    		Volume = A['Volume'];
    	end	
    	extra_text_in_vol_iss_check (Volume, A:ORIGIN ('Volume'), 'v');	
    
    	local Issue;
    	if 'citation' == config.CitationClass then
    		if utilities.is_set (Periodical) and utilities.in_array (Periodical_origin, {'journal', 'magazine', 'newspaper', 'periodical', 'work'}) or	-- {{citation}} renders issue for these 'periodicals'
    			utilities.is_set (ScriptPeriodical) and utilities.in_array (ScriptPeriodical_origin, {'script-journal', 'script-magazine', 'script-newspaper', 'script-periodical', 'script-work'}) then -- and these 'script-periodicals'
    				Issue = hyphen_to_dash (A['Issue']);
    		end
    	elseif utilities.in_array (config.CitationClass, cfg.templates_using_issue) then	-- conference & map books do not support issue; {{citation}} listed here because included in settings table
    		if not (utilities.in_array (config.CitationClass, {'conference', 'map', 'citation'}) and not (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical))) then
    			Issue = hyphen_to_dash (A['Issue']);
    		end
    	end
    	extra_text_in_vol_iss_check (Issue, A:ORIGIN ('Issue'), 'i');	
    
    	local Page;
    	local Pages;
    	local At;
    	if not utilities.in_array (config.CitationClass, cfg.templates_not_using_page) then
    		Page = A['Page'];
    		Pages = hyphen_to_dash (A['Pages']);	
    		At = A['At'];
    	end
    
    	local Edition = A['Edition'];
    	local PublicationPlace = place_check (A['PublicationPlace'], A:ORIGIN('PublicationPlace'));
    	local Place = place_check (A['Place'], A:ORIGIN('Place'));
    	
    	local PublisherName = A['PublisherName'];
    	local PublisherName_origin = A:ORIGIN('PublisherName');
    	if utilities.is_set (PublisherName) then
    		local i = 0;
    		PublisherName, i = utilities.strip_apostrophe_markup (PublisherName);	-- strip apostrophe markup so that metadata isn't contaminated; publisher is never italicized
    		if i then																-- non-zero when markup was stripped so emit an error message
    			table.insert( z.message_tail, {utilities.set_message ('err_apostrophe_markup', {PublisherName_origin}, true)});
    		end
    	end
    
    	local Newsgroup = A['Newsgroup'];											-- TODO: strip apostrophe markup?
    	local Newsgroup_origin = A:ORIGIN('Newsgroup');	
    
    	if 'newsgroup' == config.CitationClass then
    		if utilities.is_set (PublisherName) then								-- general use parameter |publisher= not allowed in cite newsgroup
    			local error_text, error_state = utilities.set_message ('err_parameter_ignored', {PublisherName_origin}, true);
    			if utilities.is_set (error_text) then
    				table.insert( z.message_tail, {error_text, error_state} );
    			end				
    		end
    
    		PublisherName = nil;													-- ensure that this parameter is unset for the time being; will be used again after COinS
    	end
    
    	local URL = A['URL']
    	local UrlAccess = is_valid_parameter_value (A['UrlAccess'], A:ORIGIN('UrlAccess'), cfg.keywords_lists['url-access'], nil);
    	
    	if not utilities.is_set (URL) and utilities.is_set (UrlAccess) then
    		UrlAccess = nil;
    		table.insert( z.message_tail, { utilities.set_message ( 'err_param_access_requires_param', {'url'}, true ) } );
    	end
    	
    	local ChapterURL = A['ChapterURL'];
    	local ChapterUrlAccess = is_valid_parameter_value (A['ChapterUrlAccess'], A:ORIGIN('ChapterUrlAccess'), cfg.keywords_lists['url-access'], nil);
    	if not utilities.is_set (ChapterURL) and utilities.is_set (ChapterUrlAccess) then
    		ChapterUrlAccess = nil;
    		table.insert( z.message_tail, { utilities.set_message ( 'err_param_access_requires_param', {A:ORIGIN('ChapterUrlAccess'):gsub ('%-access', '')}, true ) } );
    	end
    
    	local MapUrlAccess = is_valid_parameter_value (A['MapUrlAccess'], A:ORIGIN('MapUrlAccess'), cfg.keywords_lists['url-access'], nil);
    	if not utilities.is_set (A['MapURL']) and utilities.is_set (MapUrlAccess) then
    		MapUrlAccess = nil;
    		table.insert( z.message_tail, { utilities.set_message ( 'err_param_access_requires_param', {'map-url'}, true ) } );
    	end
    
    	local this_page = mw.title.getCurrentTitle();								-- also used for COinS and for language
    	local no_tracking_cats = is_valid_parameter_value (A['NoTracking'], A:ORIGIN('NoTracking'), cfg.keywords_lists['yes_true_y'], nil);
    
    	-- check this page to see if it is in one of the namespaces that cs1 is not supposed to add to the error categories
    	if not utilities.is_set (no_tracking_cats) then								-- ignore if we are already not going to categorize this page
    		if utilities.in_array (this_page.nsText, cfg.uncategorized_namespaces) then
    			no_tracking_cats = "true";											-- set no_tracking_cats
    		end
    		for _, v in ipairs (cfg.uncategorized_subpages) do						-- cycle through page name patterns
    			if this_page.text:match (v) then									-- test page name against each pattern
    				no_tracking_cats = "true";										-- set no_tracking_cats
    				break;															-- bail out if one is found
    			end
    		end
    	end
    																				-- check for extra |page=, |pages= or |at= parameters. (also sheet and sheets while we're at it)
    	utilities.select_one (args, {'page', 'p', 'pp', 'pages', 'at', 'sheet', 'sheets'}, 'err_redundant_parameters');	-- this is a dummy call simply to get the error message and category
    
    	local coins_pages;
    	
    	Page, Pages, At, coins_pages = insource_loc_get (Page, A:ORIGIN('Page'), Pages, A:ORIGIN('Pages'), At);
    
    	local NoPP = is_valid_parameter_value (A['NoPP'], A:ORIGIN('NoPP'), cfg.keywords_lists['yes_true_y'], nil);
    
    	if utilities.is_set (PublicationPlace) and utilities.is_set (Place) then	-- both |publication-place= and |place= (|location=) allowed if different
    		utilities.add_prop_cat ('location test');								-- add property cat to evaluate how often PublicationPlace and Place are used together
    		if PublicationPlace == Place then
    			Place = '';															-- unset; don't need both if they are the same
    		end
    	elseif not utilities.is_set (PublicationPlace) and utilities.is_set (Place) then	-- when only |place= (|location=) is set ...
    		PublicationPlace = Place;												-- promote |place= (|location=) to |publication-place
    	end
    
    	if PublicationPlace == Place then Place = ''; end							-- don't need both if they are the same
    	
    	local URL_origin = A:ORIGIN('URL');											-- get name of parameter that holds URL
    	local ChapterURL_origin = A:ORIGIN('ChapterURL');							-- get name of parameter that holds ChapterURL
    	local ScriptChapter = A['ScriptChapter'];
    	local ScriptChapter_origin = A:ORIGIN ('ScriptChapter');
    	local Format = A['Format'];
    	local ChapterFormat = A['ChapterFormat'];
    	local TransChapter = A['TransChapter'];
    	local TransChapter_origin = A:ORIGIN ('TransChapter');
    	local TransTitle = A['TransTitle'];
    	local ScriptTitle = A['ScriptTitle'];
    	
    	--[[
    	Parameter remapping for cite encyclopedia:
    	When the citation has these parameters:
    		|encyclopedia= and |title= then map |title= to |article= and |encyclopedia= to |title=
    		|encyclopedia= and |article= then map |encyclopedia= to |title=
    
    		|trans-title= maps to |trans-chapter= when |title= is re-mapped
    		|url= maps to |chapter-url= when |title= is remapped
    	
    	All other combinations of |encyclopedia=, |title=, and |article= are not modified
    	
    	]]
    
    	local Encyclopedia = A['Encyclopedia'];										-- used as a flag by this module and by ~/COinS
    
    	if utilities.is_set (Encyclopedia) then										-- emit error message when Encyclopedia set but template is other than {{cite encyclopedia}} or {{citation}}
    		if 'encyclopaedia' ~= config.CitationClass and 'citation' ~= config.CitationClass then
    			table.insert (z.message_tail, {utilities.set_message ('err_parameter_ignored', {A:ORIGIN ('Encyclopedia')}, true)});
    			Encyclopedia = nil;													-- unset because not supported by this template
    		end
    	end
    
    	if ('encyclopaedia' == config.CitationClass) or ('citation' == config.CitationClass and utilities.is_set (Encyclopedia)) then
    		if utilities.is_set (Periodical) and utilities.is_set (Encyclopedia) then	-- when both set emit an error
    			table.insert (z.message_tail, {utilities.set_message ('err_redundant_parameters', {utilities.wrap_style ('parameter', A:ORIGIN ('Encyclopedia')) .. ' and ' .. utilities.wrap_style ('parameter', Periodical_origin)}, true )});
    		end
    
    		if utilities.is_set (Encyclopedia) then
    			Periodical = Encyclopedia;											-- error or no, set Periodical to Encyclopedia; allow periodical without encyclopedia
    			Periodical_origin = A:ORIGIN ('Encyclopedia');
    		end
    
    		if utilities.is_set (Periodical) then									-- Periodical is set when |encyclopedia= is set
    			if utilities.is_set (Title) or utilities.is_set (ScriptTitle) then
    				if not utilities.is_set (Chapter) then
    					Chapter = Title;											-- |encyclopedia= and |title= are set so map |title= to |article= and |encyclopedia= to |title=
    					ScriptChapter = ScriptTitle;
    					ScriptChapter_origin = A:ORIGIN('ScriptTitle')
    					TransChapter = TransTitle;
    					ChapterURL = URL;
    					ChapterURL_origin = URL_origin;
    
    					ChapterUrlAccess = UrlAccess;
    
    					if not utilities.is_set (ChapterURL) and utilities.is_set (TitleLink) then
    						Chapter = utilities.make_wikilink (TitleLink, Chapter);
    					end
    					Title = Periodical;
    					ChapterFormat = Format;
    					Periodical = '';											-- redundant so unset
    					TransTitle = '';
    					URL = '';
    					Format = '';
    					TitleLink = '';
    					ScriptTitle = '';
    				end
    			elseif utilities.is_set (Chapter) then								-- |title= not set
    				Title = Periodical;												-- |encyclopedia= set and |article= set so map |encyclopedia= to |title=
    				Periodical = '';												-- redundant so unset
    			end
    		end
    	end
    
    	-- special case for cite techreport.
    	local ID = A['ID'];
    	if (config.CitationClass == "techreport") then								-- special case for cite techreport
    		if utilities.is_set (A['Number']) then									-- cite techreport uses 'number', which other citations alias to 'issue'
    			if not utilities.is_set (ID) then									-- can we use ID for the "number"?
    				ID = A['Number'];												-- yes, use it
    			else																-- ID has a value so emit error message
    				table.insert( z.message_tail, { utilities.set_message ('err_redundant_parameters', {utilities.wrap_style ('parameter', 'id') .. ' and ' .. utilities.wrap_style ('parameter', 'number')}, true )});
    			end
    		end	
    	end
    
    	-- Account for the oddity that is {{cite conference}}, before generation of COinS data.
    	local ChapterLink -- = A['ChapterLink'];									-- deprecated as a parameter but still used internally by cite episode
    	local Conference = A['Conference'];
    	local BookTitle = A['BookTitle'];
    	local TransTitle_origin = A:ORIGIN ('TransTitle');
    	if 'conference' == config.CitationClass then
    		if utilities.is_set (BookTitle) then
    			Chapter = Title;
    			Chapter_origin = 'title';
    	--		ChapterLink = TitleLink;											-- |chapter-link= is deprecated
    			ChapterURL = URL;
    			ChapterUrlAccess = UrlAccess;
    			ChapterURL_origin = URL_origin;
    			URL_origin = '';
    			ChapterFormat = Format;
    			TransChapter = TransTitle;
    			TransChapter_origin = TransTitle_origin;
    			Title = BookTitle;
    			Format = '';
    	--		TitleLink = '';
    			TransTitle = '';
    			URL = '';
    		end
    	elseif 'speech' ~= config.CitationClass then
    		Conference = '';														-- not cite conference or cite speech so make sure this is empty string
    	end
    	
    	-- CS1/2 mode
    	local Mode = is_valid_parameter_value (A['Mode'], A:ORIGIN('Mode'), cfg.keywords_lists['mode'], '');
    	-- separator character and postscript
    	local sepc, PostScript = set_style (Mode:lower(), A['PostScript'], config.CitationClass);
    	-- controls capitalization of certain static text
    	local use_lowercase = ( sepc == ',' );
    	
    	-- cite map oddities
    	local Cartography = "";
    	local Scale = "";
    	local Sheet = A['Sheet'] or '';
    	local Sheets = A['Sheets'] or '';
    	if config.CitationClass == "map" then
    		if utilities.is_set (Chapter) then
    			table.insert( z.message_tail, { utilities.set_message ( 'err_redundant_parameters', {utilities.wrap_style ('parameter', 'map') .. ' and ' .. utilities.wrap_style ('parameter', Chapter_origin)}, true ) } );	-- add error message
    		end
    		Chapter = A['Map'];
    		Chapter_origin = A:ORIGIN('Map');
    		ChapterURL = A['MapURL'];
    		ChapterURL_origin = A:ORIGIN('MapURL');
    		TransChapter = A['TransMap'];
    		ScriptChapter = A['ScriptMap']
    		ScriptChapter_origin = A:ORIGIN('ScriptMap')
    
    		ChapterUrlAccess = MapUrlAccess;
    		ChapterFormat = A['MapFormat'];
    
    		Cartography = A['Cartography'];
    		if utilities.is_set ( Cartography ) then
    			Cartography = sepc .. " " .. wrap_msg ('cartography', Cartography, use_lowercase);
    		end		
    		Scale = A['Scale'];
    		if utilities.is_set ( Scale ) then
    			Scale = sepc .. " " .. Scale;
    		end
    	end
    
    	-- Account for the oddities that are {{cite episode}} and {{cite serial}}, before generation of COinS data.
    	local Series = A['Series'];
    	if 'episode' == config.CitationClass or 'serial' == config.CitationClass then
    		local SeriesLink = A['SeriesLink'];
    
    		SeriesLink = link_title_ok (SeriesLink, A:ORIGIN ('SeriesLink'), Series, 'series');	-- check for wiki-markup in |series-link= or wiki-markup in |series= when |series-link= is set
    
    		local Network = A['Network'];
    		local Station = A['Station'];
    		local s, n = {}, {};
    																				-- do common parameters first
    		if utilities.is_set (Network) then table.insert(n, Network); end
    		if utilities.is_set (Station) then table.insert(n, Station); end
    		ID = table.concat(n, sepc .. ' ');
    		
    		if 'episode' == config.CitationClass then								-- handle the oddities that are strictly {{cite episode}}
    			local Season = A['Season'];
    			local SeriesNumber = A['SeriesNumber'];
    
    			if utilities.is_set (Season) and utilities.is_set (SeriesNumber) then	-- these are mutually exclusive so if both are set
    				table.insert( z.message_tail, { utilities.set_message ( 'err_redundant_parameters', {utilities.wrap_style ('parameter', 'season') .. ' and ' .. utilities.wrap_style ('parameter', 'seriesno')}, true ) } );		-- add error message
    				SeriesNumber = '';												-- unset; prefer |season= over |seriesno=
    			end
    																				-- assemble a table of parts concatenated later into Series
    			if utilities.is_set (Season) then table.insert(s, wrap_msg ('season', Season, use_lowercase)); end
    			if utilities.is_set (SeriesNumber) then table.insert(s, wrap_msg ('seriesnum', SeriesNumber, use_lowercase)); end
    			if utilities.is_set (Issue) then table.insert(s, wrap_msg ('episode', Issue, use_lowercase)); end
    			Issue = '';															-- unset because this is not a unique parameter
    	
    			Chapter = Title;													-- promote title parameters to chapter
    			ScriptChapter = ScriptTitle;
    			ScriptChapter_origin = A:ORIGIN('ScriptTitle');
    			ChapterLink = TitleLink;											-- alias |episode-link=
    			TransChapter = TransTitle;
    			ChapterURL = URL;
    			ChapterUrlAccess = UrlAccess;
    			ChapterURL_origin = URL_origin;
    			
    			Title = Series;														-- promote series to title
    			TitleLink = SeriesLink;
    			Series = table.concat(s, sepc .. ' ');								-- this is concatenation of season, seriesno, episode number
    
    			if utilities.is_set (ChapterLink) and not utilities.is_set (ChapterURL) then	-- link but not URL
    				Chapter = utilities.make_wikilink (ChapterLink, Chapter);
    			elseif utilities.is_set (ChapterLink) and utilities.is_set (ChapterURL) then	-- if both are set, URL links episode;
    				Series = utilities.make_wikilink (ChapterLink, Series);
    			end
    			URL = '';															-- unset
    			TransTitle = '';
    			ScriptTitle = '';
    			
    		else																	-- now oddities that are cite serial
    			Issue = '';															-- unset because this parameter no longer supported by the citation/core version of cite serial
    			Chapter = A['Episode'];												-- TODO: make |episode= available to cite episode someday?
    			if utilities.is_set (Series) and utilities.is_set (SeriesLink) then
    				Series = utilities.make_wikilink (SeriesLink, Series);
    			end
    			Series = utilities.wrap_style ('italic-title', Series);				-- series is italicized
    		end	
    	end
    	-- end of {{cite episode}} stuff
    
    	-- handle type parameter for those CS1 citations that have default values
    	local TitleType = A['TitleType'];
    	local Degree = A['Degree'];
    	if utilities.in_array (config.CitationClass, {"AV-media-notes", "interview", "mailinglist", "map", "podcast", "pressrelease", "report", "techreport", "thesis"}) then
    		TitleType = set_titletype (config.CitationClass, TitleType);
    		if utilities.is_set (Degree) and "Thesis" == TitleType then				-- special case for cite thesis
    			TitleType = Degree .. ' ' .. cfg.title_types ['thesis']:lower();
    		end
    	end
    
    	if utilities.is_set (TitleType) then										-- if type parameter is specified
    		TitleType = utilities.substitute ( cfg.messages['type'], TitleType);	-- display it in parentheses
    	-- TODO: Hack on TitleType to fix bunched parentheses problem
    	end
    
    	-- legacy: promote PublicationDate to Date if neither Date nor Year are set.
    	local Date = A['Date'];
     	local Date_origin;															-- to hold the name of parameter promoted to Date; required for date error messaging
    	local PublicationDate = A['PublicationDate'];
    	local Year = A['Year'];
    
    	if not utilities.is_set (Date) then
    		Date = Year;															-- promote Year to Date
    		Year = nil;																-- make nil so Year as empty string isn't used for CITEREF
    		if not utilities.is_set (Date) and utilities.is_set (PublicationDate) then	-- use PublicationDate when |date= and |year= are not set
    			Date = PublicationDate;												-- promote PublicationDate to Date
    			PublicationDate = '';												-- unset, no longer needed
    			Date_origin = A:ORIGIN('PublicationDate');							-- save the name of the promoted parameter
    		else
    			Date_origin = A:ORIGIN('Year');										-- save the name of the promoted parameter
    		end
    	else
    		Date_origin = A:ORIGIN('Date');											-- not a promotion; name required for error messaging
    	end
    
    	if PublicationDate == Date then PublicationDate = ''; end					-- if PublicationDate is same as Date, don't display in rendered citation
    
    	--[[
    	Go test all of the date-holding parameters for valid MOS:DATE format and make sure that dates are real dates. This must be done before we do COinS because here is where
    	we get the date used in the metadata.
    	
    	Date validation supporting code is in Module:Citation/CS1/Date_validation
    	]]
    
    	local DF = is_valid_parameter_value (A['DF'], A:ORIGIN('DF'), cfg.keywords_lists['df'], '');
    	if not utilities.is_set (DF) then
    		DF = cfg.global_df;														-- local |df= if present overrides global df set by {{use xxx date}} template
    	end
    
    	local ArchiveURL;
    	local ArchiveDate;
    	local ArchiveFormat = A['ArchiveFormat'];
    
    	ArchiveURL, ArchiveDate = archive_url_check (A['ArchiveURL'], A['ArchiveDate'])
    	ArchiveFormat = style_format (ArchiveFormat, ArchiveURL, 'archive-format', 'archive-url');
    	
    	ArchiveURL, ArchiveDate = is_unique_archive_url (ArchiveURL, URL, ChapterURL, A:ORIGIN('ArchiveURL'), ArchiveDate);		-- add error message when URL or ChapterURL == ArchiveURL
    
    	
    	local AccessDate = A['AccessDate'];
    	local LayDate = A['LayDate'];
    	local COinS_date = {};														-- holds date info extracted from |date= for the COinS metadata by Module:Date verification
    	local DoiBroken = A['DoiBroken'];
    	local Embargo = A['Embargo'];
    	local anchor_year;															-- used in the CITEREF identifier
    	do	-- create defined block to contain local variables error_message, date_parameters_list, mismatch
    		local error_message = '';
    																				-- AirDate has been promoted to Date so not necessary to check it
    		local date_parameters_list = {
    			['access-date'] = {val = AccessDate, name = A:ORIGIN ('AccessDate')},
    			['archive-date'] = {val = ArchiveDate, name = A:ORIGIN ('ArchiveDate')},
    			['date'] = {val = Date, name = Date_origin},
    			['doi-broken-date'] = {val = DoiBroken, name = A:ORIGIN ('DoiBroken')},
    			['pmc-embargo-date'] = {val = Embargo, name = A:ORIGIN ('Embargo')},
    			['lay-date'] = {val = LayDate, name = A:ORIGIN ('LayDate')},
    			['publication-date'] = {val = PublicationDate, name = A:ORIGIN ('PublicationDate')},
    			['year'] = {val = Year, name = A:ORIGIN ('Year')},
    			};
    
    		local error_list = {};
    		anchor_year, Embargo = validation.dates(date_parameters_list, COinS_date, error_list);
    
    -- start temporary Julian / Gregorian calendar uncertainty categorization
    		if COinS_date.inter_cal_cat then
    			utilities.add_prop_cat ('jul_greg_uncertainty');
    		end
    -- end temporary Julian / Gregorian calendar uncertainty categorization
    
    		if utilities.is_set (Year) and utilities.is_set (Date) then				-- both |date= and |year= not normally needed; 
    			validation.year_date_check (Year, A:ORIGIN ('Year'), Date, A:ORIGIN ('Date'), error_list);
    		end
    		
    		if 0 == #error_list then												-- error free dates only; 0 when error_list is empty
    			local modified = false;												-- flag
    			
    			if validation.edtf_transform (date_parameters_list) then			-- edtf dates to MOS compliant format
    				modified = true;
    			end
    
    			if utilities.is_set (DF) then										-- if we need to reformat dates
    				modified = validation.reformat_dates (date_parameters_list, DF);	-- reformat to DF format, use long month names if appropriate
    			end
    
    			if true == validation.date_hyphen_to_dash (date_parameters_list) then	-- convert hyphens to dashes where appropriate
    				modified = true;
    				utilities.set_message ('maint_date_format');					-- hyphens were converted so add maint category
    			end
    			
    	-- for those wikis that can and want to have English date names translated to the local language,
    	-- uncomment the next three lines.  Not supported by en.wiki (for obvious reasons)
    	-- set validation.date_name_xlate() second argument to true to translate English digits to local digits (will translate ymd dates)
    	--		if validation.date_name_xlate (date_parameters_list, false) then
    	--			modified = true;
    	--		end
    
    			if modified then													-- if the date_parameters_list values were modified
    				AccessDate = date_parameters_list['access-date'].val;			-- overwrite date holding parameters with modified values
    				ArchiveDate = date_parameters_list['archive-date'].val;
    				Date = date_parameters_list['date'].val;
    				DoiBroken = date_parameters_list['doi-broken-date'].val;
    				LayDate = date_parameters_list['lay-date'].val;
    				PublicationDate = date_parameters_list['publication-date'].val;
    			end
    		else
    			table.insert (z.message_tail, {utilities.set_message ('err_bad_date', {utilities.make_sep_list (#error_list, error_list)}, true)});	-- add this error message
    		end
    	end	-- end of do
    
    	local ID_list = {};															-- sequence table of rendered identifiers
    	local ID_list_coins = {};													-- table of identifiers and their values from args; key is same as cfg.id_handlers's key
    	local Class = A['Class'];													-- arxiv class identifier
    	
    	local ID_support = {
    		{A['ASINTLD'], 'ASIN', 'err_asintld_missing_asin', A:ORIGIN ('ASINTLD')},				
    		{DoiBroken, 'DOI', 'err_doibroken_missing_doi', A:ORIGIN ('DoiBroken')},
    		{Embargo, 'PMC', 'err_embargo_missing_pmc', A:ORIGIN ('Embargo')},
    		}
    
    	ID_list, ID_list_coins = identifiers.identifier_lists_get (args, {DoiBroken = DoiBroken, ASINTLD = A['ASINTLD'], Embargo = Embargo, Class = Class}, ID_support);
    
    	-- Account for the oddities that are {{cite arxiv}}, {{cite biorxiv}}, {{cite citeseerx}}, {{cite ssrn}}, before generation of COinS data.
    	if utilities.in_array (config.CitationClass, whitelist.preprint_template_list) then
    		if not utilities.is_set (ID_list_coins[config.CitationClass:upper()]) then 	-- |arxiv= or |eprint= required for cite arxiv; |biorxiv= & |citeseerx= required for their templates
    			table.insert (z.message_tail, {utilities.set_message ('err_' .. config.CitationClass .. '_missing', {}, true)});	-- add error message
    		end
    
    		Periodical = ({['arxiv'] = 'arXiv', ['biorxiv'] = 'bioRxiv', ['citeseerx'] = 'CiteSeerX', ['ssrn'] = 'Social Science Research Network'})[config.CitationClass];
    	end
    
    	-- Link the title of the work if no |url= was provided, but we have a |pmc= or a |doi= with |doi-access=free
    
    	if config.CitationClass == "journal" and not utilities.is_set (URL) and not utilities.is_set (TitleLink) and not utilities.in_array (cfg.keywords_xlate[Title], {'off', 'none'}) then -- TODO: remove 'none' once existing citations have been switched to 'off', so 'none' can be used as token for "no title" instead
    		if 'none' ~= cfg.keywords_xlate[auto_select] then						-- if auto-linking not disabled
     	 		if identifiers.auto_link_urls[auto_select] then						-- manual selection
    		 		URL = identifiers.auto_link_urls[auto_select];					-- set URL to be the same as identifier's external link
     				URL_origin = cfg.id_handlers[auto_select:upper()].parameters[1];	-- set URL_origin to parameter name for use in error message if citation is missing a |title=
    			elseif identifiers.auto_link_urls['pmc'] then						-- auto-select PMC
    				URL = identifiers.auto_link_urls['pmc'];						-- set URL to be the same as the PMC external link if not embargoed
    				URL_origin = cfg.id_handlers['PMC'].parameters[1];				-- set URL_origin to parameter name for use in error message if citation is missing a |title=
    			elseif identifiers.auto_link_urls['doi'] then						-- auto-select DOI
    				URL = identifiers.auto_link_urls['doi'];
    				URL_origin = cfg.id_handlers['DOI'].parameters[1];
    			end
     	 	end
    
    		if utilities.is_set (URL) and utilities.is_set (AccessDate) then		-- access date requires |url=; identifier-created URL is not |url=
    			table.insert( z.message_tail, { utilities.set_message ( 'err_accessdate_missing_url', {}, true ) } );	-- add an error message
    			AccessDate = '';													-- unset
    		end
    	end
    
    	-- At this point fields may be nil if they weren't specified in the template use.  We can use that fact.
    	-- Test if citation has no title
    	if	not utilities.is_set (Title) and not utilities.is_set (TransTitle) and not utilities.is_set (ScriptTitle) then	-- has special case for cite episode
    		table.insert( z.message_tail, { utilities.set_message ( 'err_citation_missing_title', {'episode' == config.CitationClass and 'series' or 'title'}, true ) } );
    	end
    
    	if utilities.in_array (cfg.keywords_xlate[Title], {'off', 'none'}) and
    			utilities.in_array (config.CitationClass, {'journal', 'citation'}) and
    			(utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical)) and
    			('journal' == Periodical_origin or 'script-journal' == ScriptPeriodical_origin) then	-- special case for journal cites
    				Title = '';														-- set title to empty string
    				utilities.set_message ('maint_untitled');						-- add maint cat
    	end
    
    	check_for_url ({															-- add error message when any of these parameters hold a URL
    		['title'] = Title,
    		[A:ORIGIN('Chapter')] = Chapter,
    		[Periodical_origin] = Periodical,
    		[PublisherName_origin] = PublisherName
    		});
    
    	-- COinS metadata (see <http://ocoins.info/>) for automated parsing of citation information.
    	-- handle the oddity that is cite encyclopedia and {{citation |encyclopedia=something}}. Here we presume that
    	-- when Periodical, Title, and Chapter are all set, then Periodical is the book (encyclopedia) title, Title
    	-- is the article title, and Chapter is a section within the article.  So, we remap 
    	
    	local coins_chapter = Chapter;												-- default assuming that remapping not required
    	local coins_title = Title;													-- et tu
    	if 'encyclopaedia' == config.CitationClass or ('citation' == config.CitationClass and utilities.is_set (Encyclopedia)) then
    		if utilities.is_set (Chapter) and utilities.is_set (Title) and utilities.is_set (Periodical) then		-- if all are used then
    			coins_chapter = Title;												-- remap
    			coins_title = Periodical;
    		end
    	end
    	local coins_author = a;														-- default for coins rft.au 
    	if 0 < #c then																-- but if contributor list
    		coins_author = c;														-- use that instead
    	end
    	
    	local QuotePage = A['QuotePage'];
    	local QuotePages = hyphen_to_dash (A['QuotePages']);
    
    	-- this is the function call to COinS()
    	local OCinSoutput = metadata.COinS({
    		['Periodical'] = utilities.strip_apostrophe_markup (Periodical),		-- no markup in the metadata
    		['Encyclopedia'] = Encyclopedia,										-- just a flag; content ignored by ~/COinS
    		['Chapter'] = metadata.make_coins_title (coins_chapter, ScriptChapter),	-- Chapter and ScriptChapter stripped of bold / italic wiki-markup
    		['Degree'] = Degree;													-- cite thesis only
    		['Title'] = metadata.make_coins_title (coins_title, ScriptTitle),		-- Title and ScriptTitle stripped of bold / italic wiki-markup
    		['PublicationPlace'] = PublicationPlace,
    		['Date'] = COinS_date.rftdate,											-- COinS_date has correctly formatted date if Date is valid;
    		['Season'] = COinS_date.rftssn,
    		['Quarter'] = COinS_date.rftquarter,
    		['Chron'] =  COinS_date.rftchron or (not COinS_date.rftdate and Date) or '',	-- chron but if not set and invalid date format use Date; keep this last bit?
    		['Series'] = Series,
    		['Volume'] = Volume,
    		['Issue'] = Issue,
    		['Pages'] = coins_pages or metadata.get_coins_pages (first_set ({Sheet, Sheets, Page, Pages, At, QuotePage, QuotePages}, 7)),	-- pages stripped of external links
    		['Edition'] = Edition,
    		['PublisherName'] = PublisherName or Newsgroup,							-- any apostrophe markup already removed from PublisherName
    		['URL'] = first_set ({ChapterURL, URL}, 2),
    		['Authors'] = coins_author,
    		['ID_list'] = ID_list_coins,
    		['RawPage'] = this_page.prefixedText,
    	}, config.CitationClass);
    
    	-- Account for the oddities that are {{cite arxiv}}, {{cite biorxiv}}, {{cite citeseerx}}, and {{cite ssrn}} AFTER generation of COinS data.
    	if utilities.in_array (config.CitationClass, whitelist.preprint_template_list) then	-- we have set rft.jtitle in COinS to arXiv, bioRxiv, CiteSeerX, or ssrn now unset so it isn't displayed
    		Periodical = '';														-- periodical not allowed in these templates; if article has been published, use cite journal
    	end
    
    	-- special case for cite newsgroup.  Do this after COinS because we are modifying Publishername to include some static text
    	if 'newsgroup' == config.CitationClass and utilities.is_set (Newsgroup) then
    		PublisherName = utilities.substitute (cfg.messages['newsgroup'], external_link( 'news:' .. Newsgroup, Newsgroup, Newsgroup_origin, nil ));
    	end
    
    	local Editors;
    	local EditorCount;															-- used only for choosing {ed.) or (eds.) annotation at end of editor name-list
    	local Contributors;															-- assembled contributors name list
    	local contributor_etal;
    	local Translators;															-- assembled translators name list
    	local translator_etal;
    	local t = {};																-- translators list from |translator-lastn= / translator-firstn= pairs
    	t = extract_names (args, 'TranslatorList');									-- fetch translator list from |translatorn= / |translator-lastn=, -firstn=, -linkn=, -maskn=
    	local Interviewers;															
    	local interviewers_list = {};					
    	interviewers_list = extract_names (args, 'InterviewerList');				-- process preferred interviewers parameters
    	local interviewer_etal;
    	
    	-- Now perform various field substitutions.
    	-- We also add leading spaces and surrounding markup and punctuation to the
    	-- various parts of the citation, but only when they are non-nil.
    	do
    		local last_first_list;
    		local control = { 
    			format = NameListStyle,												-- empty string or 'vanc'
    			maximum = nil,														-- as if display-authors or display-editors not set
    			mode = Mode
    		};
    
    		do																		-- do editor name list first because the now unsupported coauthors used to modify control table
    			control.maximum , editor_etal = get_display_names (A['DisplayEditors'], #e, 'editors', editor_etal, A:ORIGIN ('DisplayEditors'));
    			Editors, EditorCount = list_people (control, e, editor_etal);
    
    			if 1 == EditorCount and (true == editor_etal or 1 < #e) then		-- only one editor displayed but includes etal then 
    				EditorCount = 2;												-- spoof to display (eds.) annotation
    			end
    		end
    		do																		-- now do interviewers
    			control.maximum, interviewer_etal = get_display_names (A['DisplayInterviewers'], #interviewers_list, 'interviewers', interviewer_etal, A:ORIGIN ('DisplayInterviewers'));
    			Interviewers = list_people (control, interviewers_list, interviewer_etal);
    		end
    		do																		-- now do translators
    			control.maximum, translator_etal = get_display_names (A['DisplayTranslators'], #t, 'translators', translator_etal, A:ORIGIN ('DisplayTranslators'));
    			Translators = list_people (control, t, translator_etal);
    		end
    		do																		-- now do contributors
    			control.maximum, contributor_etal = get_display_names (A['DisplayContributors'], #c, 'contributors', contributor_etal, A:ORIGIN ('DisplayContributors'));
    			Contributors = list_people (control, c, contributor_etal);
    		end
    		do																		-- now do authors
    			control.maximum, author_etal = get_display_names (A['DisplayAuthors'], #a, 'authors', author_etal, A:ORIGIN ('DisplayAuthors'));
    
    			last_first_list = list_people (control, a, author_etal);
    
    			if utilities.is_set (Authors) then
    				Authors, author_etal = name_has_etal (Authors, author_etal, false, 'authors');	-- find and remove variations on et al.
    				if author_etal then
    					Authors = Authors .. ' ' .. cfg.messages['et al'];			-- add et al. to authors parameter
    				end
    			else
    				Authors = last_first_list;										-- either an author name list or an empty string
    			end
    		end																		-- end of do
    	
    		if utilities.is_set (Authors) and utilities.is_set (Collaboration) then
    			Authors = Authors .. ' (' .. Collaboration .. ')';					-- add collaboration after et al.
    		end
    
    	end
    
    	local ConferenceFormat = A['ConferenceFormat'];
    	local ConferenceURL = A['ConferenceURL'];
    	ConferenceFormat = style_format (ConferenceFormat, ConferenceURL, 'conference-format', 'conference-url');
    	Format = style_format (Format, URL, 'format', 'url');
    
    	-- special case for chapter format so no error message or cat when chapter not supported
    	if not (utilities.in_array (config.CitationClass, {'web', 'news', 'journal', 'magazine', 'pressrelease', 'podcast', 'newsgroup', 'arxiv', 'biorxiv', 'citeseerx', 'ssrn'}) or
    		('citation' == config.CitationClass and (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical)) and not utilities.is_set (Encyclopedia))) then
    			ChapterFormat = style_format (ChapterFormat, ChapterURL, 'chapter-format', 'chapter-url');
    	end
    
    	if not utilities.is_set (URL) then
    		if utilities.in_array (config.CitationClass, {"web", "podcast", "mailinglist"}) or		-- |url= required for cite web, cite podcast, and cite mailinglist
    			('citation' == config.CitationClass and ('website' == Periodical_origin or 'script-website' == ScriptPeriodical_origin)) then	-- and required for {{citation}} with |website= or |script-website=
    				table.insert( z.message_tail, { utilities.set_message ( 'err_cite_web_url', {}, true ) } );
    		end
    		
    		-- do we have |accessdate= without either |url= or |chapter-url=?
    		if utilities.is_set (AccessDate) and not utilities.is_set (ChapterURL) then		-- ChapterURL may be set when URL is not set;
    			table.insert( z.message_tail, { utilities.set_message ( 'err_accessdate_missing_url', {}, true ) } );
    			AccessDate = '';
    		end
    	end
    
    	local UrlStatus = is_valid_parameter_value (A['UrlStatus'], A:ORIGIN('UrlStatus'), cfg.keywords_lists['url-status'], '');
    	local OriginalURL
    	local OriginalURL_origin
    	local OriginalFormat
    	local OriginalAccess;
    	UrlStatus = UrlStatus:lower();												-- used later when assembling archived text
    	if utilities.is_set ( ArchiveURL ) then
    		if utilities.is_set (ChapterURL) then 									-- if chapter-url= is set apply archive url to it
    			OriginalURL = ChapterURL;											-- save copy of source chapter's url for archive text
    			OriginalURL_origin = ChapterURL_origin;								-- name of |chapter-url= parameter for error messages
    			OriginalFormat = ChapterFormat;										-- and original |chapter-format=
    
    			if 'live' ~= UrlStatus then
    				ChapterURL = ArchiveURL											-- swap-in the archive's URL
    				ChapterURL_origin = A:ORIGIN('ArchiveURL')						-- name of |archive-url= parameter for error messages
    				ChapterFormat = ArchiveFormat or '';							-- swap in archive's format
    				ChapterUrlAccess = nil;											-- restricted access levels do not make sense for archived URLs
    			end
    		elseif utilities.is_set (URL) then
    			OriginalURL = URL;													-- save copy of original source URL
    			OriginalURL_origin = URL_origin;									-- name of URL parameter for error messages
    			OriginalFormat = Format; 											-- and original |format=
    			OriginalAccess = UrlAccess;
    
    			if 'live' ~= UrlStatus then											-- if URL set then |archive-url= applies to it
    				URL = ArchiveURL												-- swap-in the archive's URL
    				URL_origin = A:ORIGIN('ArchiveURL')								-- name of archive URL parameter for error messages
    				Format = ArchiveFormat or '';									-- swap in archive's format
    				UrlAccess = nil;												-- restricted access levels do not make sense for archived URLs
    			end
     		end
    	end
    
    	if utilities.in_array (config.CitationClass, {'web', 'news', 'journal', 'magazine', 'pressrelease', 'podcast', 'newsgroup', 'arxiv', 'biorxiv', 'citeseerx', 'ssrn'}) or	-- if any of the 'periodical' cites except encyclopedia
    		('citation' == config.CitationClass and (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical)) and not utilities.is_set (Encyclopedia)) then
    			local chap_param;
    			if utilities.is_set (Chapter) then									-- get a parameter name from one of these chapter related meta-parameters
    				chap_param = A:ORIGIN ('Chapter')
    			elseif utilities.is_set (TransChapter) then
    				chap_param = A:ORIGIN ('TransChapter')
    			elseif utilities.is_set (ChapterURL) then
    				chap_param = A:ORIGIN ('ChapterURL')
    			elseif utilities.is_set (ScriptChapter) then
    				chap_param = ScriptChapter_origin;
    			else utilities.is_set (ChapterFormat)
    				chap_param = A:ORIGIN ('ChapterFormat')
    			end
    
    			if utilities.is_set (chap_param) then								-- if we found one
    				table.insert( z.message_tail, { utilities.set_message ( 'err_chapter_ignored', {chap_param}, true ) } );	-- add error message
    				Chapter = '';													-- and set them to empty string to be safe with concatenation
    				TransChapter = '';
    				ChapterURL = '';
    				ScriptChapter = '';
    				ChapterFormat = '';
    			end
    	else																		-- otherwise, format chapter / article title
    		local no_quotes = false;												-- default assume that we will be quoting the chapter parameter value
    		if utilities.is_set (Contribution) and 0 < #c then						-- if this is a contribution with contributor(s)
    			if utilities.in_array (Contribution:lower(), cfg.keywords_lists.contribution) then	-- and a generic contribution title
    				no_quotes = true;												-- then render it unquoted
    			end
    		end
    
    		Chapter = format_chapter_title (ScriptChapter, ScriptChapter_origin, Chapter, Chapter_origin, TransChapter, TransChapter_origin, ChapterURL, ChapterURL_origin, no_quotes, ChapterUrlAccess);		-- Contribution is also in Chapter
    		if utilities.is_set (Chapter) then
    			Chapter = Chapter .. ChapterFormat ;
    			if 'map' == config.CitationClass and utilities.is_set (TitleType) then
    				Chapter = Chapter .. ' ' .. TitleType;							-- map annotation here; not after title
    			end
    			Chapter = Chapter .. sepc .. ' ';
    		elseif utilities.is_set (ChapterFormat) then							-- |chapter= not set but |chapter-format= is so ...
    			Chapter = ChapterFormat .. sepc .. ' ';								-- ... ChapterFormat has error message, we want to see it
    		end
    	end
    
    	-- Format main title
    	local plain_title = false;
    	local accept_title;
    	Title, accept_title = utilities.has_accept_as_written (Title, true);		-- remove accept-this-as-written markup when it wraps all of <Title>
    	if accept_title and ('' == Title) then										-- only support forced empty for now "(())"
    		Title = cfg.messages['notitle'];										-- replace by predefined "No title" message
    			-- TODO: utilities.set_message ( 'err_redundant_parameters', ...);	-- issue proper error message instead of muting	 
    			ScriptTitle = '';													-- just mute for now	 
    			TransTitle = '';													-- just mute for now
     		plain_title = true;														-- suppress text decoration for descriptive title
    		utilities.set_message ('maint_untitled');								-- add maint cat
    	end
    
    	if not accept_title then -- <Title> not wrapped in accept-as-written markup
    		if '...' == Title:sub (-3) then											-- if ellipsis is the last three characters of |title=
    			Title = Title:gsub ('(%.%.%.)%.+$', '%1');							-- limit the number of dots to three
    		elseif not mw.ustring.find (Title, '%.%s*%a%.$') and					-- end of title is not a 'dot-(optional space-)letter-dot' initialism ...
    			not mw.ustring.find (Title, '%s+%a%.$') then						-- ...and not a 'space-letter-dot' initial (''Allium canadense'' L.)
    				Title = mw.ustring.gsub(Title, '%' .. sepc .. '$', '');			-- remove any trailing separator character; sepc and ms.ustring() here for languages that use multibyte separator characters
    		end
    
    		if utilities.is_set (ArchiveURL) and is_archived_copy (Title) then
    			utilities.set_message ('maint_archived_copy');						-- add maintenance category before we modify the content of Title
    		end
    
    		if is_generic_title (Title) then
    			table.insert (z.message_tail, {utilities.set_message ( 'err_generic_title', {}, true ) } );	-- set an error message
    		end
    	end
    
    	if (not plain_title) and (utilities.in_array (config.CitationClass, {'web', 'news', 'journal', 'magazine', 'pressrelease', 'podcast', 'newsgroup', 'mailinglist', 'interview', 'arxiv', 'biorxiv', 'citeseerx', 'ssrn'}) or
    		('citation' == config.CitationClass and (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical)) and not utilities.is_set (Encyclopedia)) or
    		('map' == config.CitationClass and (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical)))) then		-- special case for cite map when the map is in a periodical treat as an article
    			Title = kern_quotes (Title);										-- if necessary, separate title's leading and trailing quote marks from module provided quote marks
    			Title = utilities.wrap_style ('quoted-title', Title);
    			Title = script_concatenate (Title, ScriptTitle, 'script-title');	-- <bdi> tags, lang attribute, categorization, etc.; must be done after title is wrapped
    			TransTitle = utilities.wrap_style ('trans-quoted-title', TransTitle );
    	elseif plain_title or ('report' == config.CitationClass) then								-- no styling for cite report and descriptive titles (otherwise same as above)
    		Title = script_concatenate (Title, ScriptTitle, 'script-title');		-- <bdi> tags, lang attribute, categorization, etc.; must be done after title is wrapped
    		TransTitle = utilities.wrap_style ('trans-quoted-title', TransTitle );				-- for cite report, use this form for trans-title
    	else
    		Title = utilities.wrap_style ('italic-title', Title);
    		Title = script_concatenate (Title, ScriptTitle, 'script-title');		-- <bdi> tags, lang attribute, categorization, etc.; must be done after title is wrapped
    		TransTitle = utilities.wrap_style ('trans-italic-title', TransTitle);
    	end
    
    	local TransError = "";
    	if utilities.is_set (TransTitle) then
    		if utilities.is_set (Title) then
    			TransTitle = " " .. TransTitle;
    		else
    			TransError = " " .. utilities.set_message ( 'err_trans_missing_title', {'title'} );
    		end
    	end
    
    	if utilities.is_set (Title) then											-- TODO: is this the right place to be making Wikisource URLs?
    		if utilities.is_set (TitleLink) and utilities.is_set (URL) then
    			table.insert( z.message_tail, { utilities.set_message ( 'err_wikilink_in_url', {}, true ) } );	-- set an error message because we can't have both
    			TitleLink = '';														-- unset
    		end
    	
    		if not utilities.is_set (TitleLink) and utilities.is_set (URL) then
    			Title = external_link (URL, Title, URL_origin, UrlAccess) .. TransTitle .. TransError .. Format;
    			URL = '';															-- unset these because no longer needed
    			Format = "";
    		elseif utilities.is_set (TitleLink) and not utilities.is_set (URL) then
    			local ws_url;
    			ws_url = wikisource_url_make (TitleLink);							-- ignore ws_label return; not used here
    			if ws_url then
    				Title = external_link (ws_url, Title .. '&nbsp;', 'ws link in title-link');	-- space char after Title to move icon away from italic text; TODO: a better way to do this?
    				Title = utilities.substitute (cfg.presentation['interwiki-icon'], {cfg.presentation['class-wikisource'], TitleLink, Title});				
    				Title = Title .. TransTitle .. TransError;
    			else
    				Title = utilities.make_wikilink (TitleLink, Title) .. TransTitle .. TransError;
    			end
    		else
    			local ws_url, ws_label, L;											-- Title has italic or quote markup by the time we get here which causes is_wikilink() to return 0 (not a wikilink)
    			ws_url, ws_label, L = wikisource_url_make (Title:gsub('^[\'"]*(.-)[\'"]*$', '%1'));	-- make ws URL from |title= interwiki link (strip italic or quote markup); link portion L becomes tooltip label
    			if ws_url then
    				Title = Title:gsub ('%b[]', ws_label);							-- replace interwiki link with ws_label to retain markup
    				Title = external_link (ws_url, Title .. '&nbsp;', 'ws link in title');	-- space char after Title to move icon away from italic text; TODO: a better way to do this?
    				Title = utilities.substitute (cfg.presentation['interwiki-icon'], {cfg.presentation['class-wikisource'], L, Title});				
    				Title = Title .. TransTitle .. TransError;
    			else
    				Title = Title .. TransTitle .. TransError;
    			end
    		end
    	else
    		Title = TransTitle .. TransError;
    	end
    
    	if utilities.is_set (Place) then
    		Place = " " .. wrap_msg ('written', Place, use_lowercase) .. sepc .. " ";
    	end
    
    	local ConferenceURL_origin = A:ORIGIN('ConferenceURL');						-- get name of parameter that holds ConferenceURL
    	if utilities.is_set (Conference) then
    		if utilities.is_set (ConferenceURL) then
    			Conference = external_link( ConferenceURL, Conference, ConferenceURL_origin, nil );
    		end
    		Conference = sepc .. " " .. Conference .. ConferenceFormat;
    	elseif utilities.is_set (ConferenceURL) then
    		Conference = sepc .. " " .. external_link( ConferenceURL, nil, ConferenceURL_origin, nil );
    	end
    
    	local Position = '';
    	if not utilities.is_set (Position) then
    		local Minutes = A['Minutes'];
    		local Time = A['Time'];
    
    		if utilities.is_set (Minutes) then
    			if utilities.is_set (Time) then
    				table.insert( z.message_tail, { utilities.set_message ( 'err_redundant_parameters', {utilities.wrap_style ('parameter', 'minutes') .. ' and ' .. utilities.wrap_style ('parameter', 'time')}, true ) } );
    			end
    			Position = " " .. Minutes .. " " .. cfg.messages['minutes'];
    		else
    			if utilities.is_set (Time) then
    				local TimeCaption = A['TimeCaption']
    				if not utilities.is_set (TimeCaption) then
    					TimeCaption = cfg.messages['event'];
    					if sepc ~= '.' then
    						TimeCaption = TimeCaption:lower();
    					end
    				end
    				Position = " " .. TimeCaption .. " " .. Time;
    			end
    		end
    	else
    		Position = " " .. Position;
    		At = '';
    	end
    
    	Page, Pages, Sheet, Sheets = format_pages_sheets (Page, Pages, Sheet, Sheets, config.CitationClass, Periodical_origin, sepc, NoPP, use_lowercase);
    
    	At = utilities.is_set (At) and (sepc .. " " .. At) or "";
    	Position = utilities.is_set (Position) and (sepc .. " " .. Position) or "";
    	if config.CitationClass == 'map' then
    		local Sections = A['Sections'];											-- Section (singular) is an alias of Chapter so set earlier
    		local Inset = A['Inset'];
    		
    		if utilities.is_set ( Inset ) then
    			Inset = sepc .. " " .. wrap_msg ('inset', Inset, use_lowercase);
    		end			
    
    		if utilities.is_set ( Sections ) then
    			Section = sepc .. " " .. wrap_msg ('sections', Sections, use_lowercase);
    		elseif utilities.is_set ( Section ) then
    			Section = sepc .. " " .. wrap_msg ('section', Section, use_lowercase);
    		end
    		At = At .. Inset .. Section;		
    	end	
    
    	local Others = A['Others'];
    	if utilities.is_set (Others) and 0 == #a and 0 == #e then					-- add maint cat when |others= has value and used without |author=, |editor=
    		if config.CitationClass == "AV-media-notes"
    		or config.CitationClass == "audio-visual" then							-- special maint for AV/M which has a lot of 'false' positives right now
    			utilities.set_message ('maint_others_avm')
    		else
    			utilities.set_message ('maint_others');
    		end
    	end
    	Others = utilities.is_set (Others) and (sepc .. " " .. Others) or "";
    	
    	if utilities.is_set (Translators) then
    		Others = safe_join ({sepc .. ' ', wrap_msg ('translated', Translators, use_lowercase), Others}, sepc);
    	end
    	if utilities.is_set (Interviewers) then
    		Others = safe_join ({sepc .. ' ', wrap_msg ('interview', Interviewers, use_lowercase), Others}, sepc);
    	end
    	
    	local TitleNote = A['TitleNote'];
    	TitleNote = utilities.is_set (TitleNote) and (sepc .. " " .. TitleNote) or "";
    	if utilities.is_set (Edition) then
    		if Edition:match ('%f[%a][Ee]d%n?%.?$') or Edition:match ('%f[%a][Ee]dition$') then -- Ed, ed, Ed., ed., Edn, edn, Edn., edn.
    			table.insert( z.message_tail, { utilities.set_message ( 'err_extra_text_edition')}); -- add error
    		end
    		Edition = " " .. wrap_msg ('edition', Edition);
    	else
    		Edition = '';
    	end
    
    	Series = utilities.is_set (Series) and wrap_msg ('series', {sepc, Series}) or "";	-- not the same as SeriesNum
    	local Agency = A['Agency'];
    	Agency = utilities.is_set (Agency) and wrap_msg ('agency', {sepc, Agency}) or "";
    	Volume = format_volume_issue (Volume, Issue, config.CitationClass, Periodical_origin, sepc, use_lowercase);
    
    	if utilities.is_set (AccessDate) then
    		local retrv_text = " " .. cfg.messages['retrieved']
    
    		AccessDate = nowrap_date (AccessDate);									-- wrap in nowrap span if date in appropriate format
    		if (sepc ~= ".") then retrv_text = retrv_text:lower() end				-- if mode is cs2, lower case
    		AccessDate = utilities.substitute (retrv_text, AccessDate);				-- add retrieved text
    
    		AccessDate = utilities.substitute (cfg.presentation['accessdate'], {sepc, AccessDate});	-- allow editors to hide accessdates
    	end
    	
    	if utilities.is_set (ID) then ID = sepc .. " " .. ID; end
    	
    	local Docket = A['Docket'];
       	if "thesis" == config.CitationClass and utilities.is_set (Docket) then
    		ID = sepc .. " Docket " .. Docket .. ID;
    	end
       	if "report" == config.CitationClass and utilities.is_set (Docket) then		-- for cite report when |docket= is set
    		ID = sepc .. ' ' .. Docket;												-- overwrite ID even if |id= is set
    	end
    
    	if utilities.is_set (URL) then
    		URL = " " .. external_link( URL, nil, URL_origin, UrlAccess );
    	end
    
    	local Quote = A['Quote'];
    	local TransQuote = A['TransQuote'];
    	local ScriptQuote = A['ScriptQuote'];
    	if utilities.is_set (Quote) or utilities.is_set (TransQuote) or utilities.is_set (ScriptQuote) then
    
    		if utilities.is_set (Quote) then
    			if Quote:sub(1, 1) == '"' and Quote:sub(-1, -1) == '"' then			-- if first and last characters of quote are quote marks
    				Quote = Quote:sub(2, -2);										-- strip them off
    			end
    		end
    
    		Quote = utilities.wrap_style ('quoted-text', Quote );					-- wrap in <q>...</q> tags
    	
    		if utilities.is_set (ScriptQuote) then
    			Quote = script_concatenate (Quote, ScriptQuote, 'script-quote');	-- <bdi> tags, lang attribute, categorization, etc.; must be done after quote is wrapped
    		end
    
    		if utilities.is_set (TransQuote) then
    			if TransQuote:sub(1, 1) == '"' and TransQuote:sub(-1, -1) == '"' then -- if first and last characters of |trans-quote are quote marks
    				TransQuote = TransQuote:sub(2, -2); -- strip them off
    			end
    			Quote = Quote .. " " .. utilities.wrap_style ('trans-quoted-title', TransQuote );
    		end
    
    		if utilities.is_set (QuotePage) or utilities.is_set (QuotePages) then	-- add page prefix
    			local quote_prefix = '';
    			if utilities.is_set (QuotePage) then
    				extra_text_in_page_check (QuotePage, 'quote-page');				-- add to maint cat if |quote-page= value begins with what looks like p., pp., etc.
    				if not NoPP then
    					quote_prefix = utilities.substitute (cfg.messages['p-prefix'], {sepc, QuotePage}), '', '', '';
    				else
    					quote_prefix = utilities.substitute (cfg.messages['nopp'], {sepc, QuotePage}), '', '', '';
    				end
    			elseif utilities.is_set (QuotePages) then
    				extra_text_in_page_check (QuotePages, 'quote-pages');			-- add to maint cat if |quote-pages= value begins with what looks like p., pp., etc.
    				if tonumber(QuotePages) ~= nil and not NoPP then				-- if only digits, assume single page
    					quote_prefix = utilities.substitute (cfg.messages['p-prefix'], {sepc, QuotePages}), '', '';
    				elseif not NoPP then
    					quote_prefix = utilities.substitute (cfg.messages['pp-prefix'], {sepc, QuotePages}), '', '';
    				else
    					quote_prefix = utilities.substitute (cfg.messages['nopp'], {sepc, QuotePages}), '', '';
    				end
    			end
                            
    			Quote = quote_prefix .. ": " .. Quote;
    		else
    			Quote = sepc .. " " .. Quote;
    		end
    
    		PostScript = "";														-- cs1|2 does not supply terminal punctuation when |quote= is set
    	end
    	
    	-- We check length of PostScript here because it will have been nuked by
    	-- the quote parameters. We'd otherwise emit a message even if there wasn't
    	-- a displayed postscript.
    	-- TODO: Should the max size (1) be configurable?
    	-- TODO: Should we check a specific pattern?
    	if utilities.is_set(PostScript) and mw.ustring.len(PostScript) > 1 then
    		utilities.set_message('maint_postscript')
    	end
    	
    	local Archived
    	if utilities.is_set (ArchiveURL) then
    		local arch_text;
    		if not utilities.is_set (ArchiveDate) then
    			ArchiveDate = utilities.set_message ('err_archive_missing_date');
    		end
    		if "live" == UrlStatus then
    			arch_text = cfg.messages['archived'];
    			if sepc ~= "." then arch_text = arch_text:lower() end
    			Archived = sepc .. " " .. utilities.substitute ( cfg.messages['archived-live'],
    				{ external_link( ArchiveURL, arch_text, A:ORIGIN('ArchiveURL'), nil ) .. ArchiveFormat, ArchiveDate } );
    			if not utilities.is_set (OriginalURL) then
    				Archived = Archived .. " " .. utilities.set_message ('err_archive_missing_url');							   
    			end
    		elseif utilities.is_set (OriginalURL) then								-- UrlStatus is empty, 'dead', 'unfit', 'usurped', 'bot: unknown'
    			if utilities.in_array (UrlStatus, {'unfit', 'usurped', 'bot: unknown'}) then
    				arch_text = cfg.messages['archived-unfit'];
    				if sepc ~= "." then arch_text = arch_text:lower() end
    				Archived = sepc .. " " .. arch_text .. ArchiveDate;				-- format already styled
    				if 'bot: unknown' == UrlStatus then
    					utilities.set_message ('maint_bot_unknown');				-- and add a category if not already added
    				else
    					utilities.set_message ('maint_unfit');						-- and add a category if not already added
    				end
    			else																-- UrlStatus is empty, 'dead'
    				arch_text = cfg.messages['archived-dead'];
    				if sepc ~= "." then arch_text = arch_text:lower() end
    				Archived = sepc .. " " .. utilities.substitute ( arch_text,
    					{ external_link( OriginalURL, cfg.messages['original'], OriginalURL_origin, OriginalAccess ) .. OriginalFormat, ArchiveDate } );	-- format already styled
    			end	
    		else																	-- OriginalUrl not set
    			arch_text = cfg.messages['archived-missing'];
    			if sepc ~= "." then arch_text = arch_text:lower() end
    			Archived = sepc .. " " .. utilities.substitute ( arch_text, 
    				{ utilities.set_message ('err_archive_missing_url'), ArchiveDate } );
    		end
    	elseif utilities.is_set (ArchiveFormat) then
    		Archived = ArchiveFormat;												-- if set and ArchiveURL not set ArchiveFormat has error message
    	else
    		Archived = ""
    	end
    	
    	local Lay = '';
    	local LaySource = A['LaySource'];
    	local LayURL = A['LayURL'];
    	local LayFormat = A['LayFormat'];
    	LayFormat = style_format (LayFormat, LayURL, 'lay-format', 'lay-url');
    	if utilities.is_set (LayURL) then
    		if utilities.is_set (LayDate) then LayDate = " (" .. LayDate .. ")" end
    		if utilities.is_set (LaySource) then 
    			LaySource = " &ndash; ''" .. utilities.safe_for_italics (LaySource) .. "''";
    		else
    			LaySource = "";
    		end
    		if sepc == '.' then
    			Lay = sepc .. " " .. external_link( LayURL, cfg.messages['lay summary'], A:ORIGIN('LayURL'), nil ) .. LayFormat .. LaySource .. LayDate
    		else
    			Lay = sepc .. " " .. external_link( LayURL, cfg.messages['lay summary']:lower(), A:ORIGIN('LayURL'), nil ) .. LayFormat .. LaySource .. LayDate
    		end			
    	elseif utilities.is_set (LayFormat) then									-- Test if |lay-format= is given without giving a |lay-url=
    		Lay = sepc .. LayFormat;												-- if set and LayURL not set, then LayFormat has error message
    	end
    
    	local TranscriptURL = A['TranscriptURL']
    	local TranscriptFormat = A['TranscriptFormat'];
    	TranscriptFormat = style_format (TranscriptFormat, TranscriptURL, 'transcript-format', 'transcripturl');
    	local Transcript = A['Transcript'];
    	local TranscriptURL_origin = A:ORIGIN('TranscriptURL');						-- get name of parameter that holds TranscriptURL
    	if utilities.is_set (Transcript) then
    		if utilities.is_set (TranscriptURL) then
    			Transcript = external_link( TranscriptURL, Transcript, TranscriptURL_origin, nil );
    		end
    		Transcript = sepc .. ' ' .. Transcript .. TranscriptFormat;
    	elseif utilities.is_set (TranscriptURL) then
    		Transcript = external_link( TranscriptURL, nil, TranscriptURL_origin, nil );
    	end
    
    	local Publisher;
    	if utilities.is_set (PublicationDate) then
    		PublicationDate = wrap_msg ('published', PublicationDate);
    	end
    	if utilities.is_set (PublisherName) then
    		if utilities.is_set (PublicationPlace) then
    			Publisher = sepc .. " " .. PublicationPlace .. ": " .. PublisherName .. PublicationDate;
    		else
    			Publisher = sepc .. " " .. PublisherName .. PublicationDate;  
    		end			
    	elseif utilities.is_set (PublicationPlace) then 
    		Publisher= sepc .. " " .. PublicationPlace .. PublicationDate;
    	else 
    		Publisher = PublicationDate;
    	end
    	
    	local TransPeriodical =  A['TransPeriodical'];
    	local TransPeriodical_origin =  A:ORIGIN ('TransPeriodical');
    	-- Several of the above rely upon detecting this as nil, so do it last.
    	if (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical) or utilities.is_set (TransPeriodical)) then
    		if utilities.is_set (Title) or utilities.is_set (TitleNote) then 
    			Periodical = sepc .. " " .. format_periodical (ScriptPeriodical, ScriptPeriodical_origin, Periodical, TransPeriodical, TransPeriodical_origin);
    		else 
    			Periodical = format_periodical (ScriptPeriodical, ScriptPeriodical_origin, Periodical, TransPeriodical, TransPeriodical_origin);
    		end
    	end
    	
    	local Language = A['Language'];
    	if utilities.is_set (Language) then
    		Language = language_parameter (Language);								-- format, categories, name from ISO639-1, etc.
    	else
    		Language='';															-- language not specified so make sure this is an empty string;
    	--[[ TODO: need to extract the wrap_msg from language_parameter
    	so that we can solve parentheses bunching problem with Format/Language/TitleType
    	]]
    	end
    
    	--[[
    	Handle the oddity that is cite speech.  This code overrides whatever may be the value assigned to TitleNote (through |department=) and forces it to be " (Speech)" so that
    	the annotation directly follows the |title= parameter value in the citation rather than the |event= parameter value (if provided).
    	]]
    	if "speech" == config.CitationClass then									-- cite speech only
    		TitleNote = " (Speech)";												-- annotate the citation
    		if utilities.is_set (Periodical) then									-- if Periodical, perhaps because of an included |website= or |journal= parameter 
    			if utilities.is_set (Conference) then								-- and if |event= is set
    				Conference = Conference .. sepc .. " ";							-- then add appropriate punctuation to the end of the Conference variable before rendering
    			end
    		end
    	end
    
    	-- Piece all bits together at last.  Here, all should be non-nil.
    	-- We build things this way because it is more efficient in LUA
    	-- not to keep reassigning to the same string variable over and over.
    
    	local tcommon;
    	local tcommon2;																-- used for book cite when |contributor= is set
    	
    	if utilities.in_array (config.CitationClass, {"journal", "citation"}) and utilities.is_set (Periodical) then
    		if utilities.is_set (Others) then Others = safe_join ({Others, sepc .. " "}, sepc) end		-- add terminal punctuation & space; check for dup sepc; TODO why do we need to do this here?
    		tcommon = safe_join( {Others, Title, TitleNote, Conference, Periodical, Format, TitleType, Series, Language, Edition, Publisher, Agency, Volume}, sepc );
    	elseif utilities.in_array (config.CitationClass, {"book", "citation"}) and not utilities.is_set (Periodical) then		-- special cases for book cites
    		if utilities.is_set (Contributors) then									-- when we are citing foreword, preface, introduction, etc.
    			tcommon = safe_join( {Title, TitleNote}, sepc );					-- author and other stuff will come after this and before tcommon2
    			tcommon2 = safe_join( {Conference, Periodical, Format, TitleType, Series, Language, Volume, Others, Edition, Publisher, Agency}, sepc );
    		else
    			tcommon = safe_join( {Title, TitleNote, Conference, Periodical, Format, TitleType, Series, Language, Volume, Others, Edition, Publisher, Agency}, sepc );
    		end
    
    	elseif 'map' == config.CitationClass then									-- special cases for cite map
    		if utilities.is_set (Chapter) then										-- map in a book; TitleType is part of Chapter
    			tcommon = safe_join( {Title, Format, Edition, Scale, Series, Language, Cartography, Others, Publisher, Volume}, sepc );
    		elseif utilities.is_set (Periodical) then								-- map in a periodical
    			tcommon = safe_join( {Title, TitleType, Format, Periodical, Scale, Series, Language, Cartography, Others, Publisher, Volume}, sepc );
    		else																	-- a sheet or stand-alone map
    			tcommon = safe_join( {Title, TitleType, Format, Edition, Scale, Series, Language, Cartography, Others, Publisher}, sepc );
    		end
    		
    	elseif 'episode' == config.CitationClass then								-- special case for cite episode
    		tcommon = safe_join( {Title, TitleNote, TitleType, Series, Language, Edition, Publisher}, sepc );
    
    	else																		-- all other CS1 templates
    		tcommon = safe_join( {Title, TitleNote, Conference, Periodical, Format, TitleType, Series, Language, 
    			Volume, Others, Edition, Publisher, Agency}, sepc );
    	end
    	
    	if #ID_list > 0 then
    		ID_list = safe_join( { sepc .. " ",  table.concat( ID_list, sepc .. " " ), ID }, sepc );
    	else
    		ID_list = ID;
    	end
    	
    	local Via = A['Via'];
    	Via = utilities.is_set (Via) and  wrap_msg ('via', Via) or '';
    	local idcommon;
    	if 'audio-visual' == config.CitationClass or 'episode' == config.CitationClass then	-- special case for cite AV media & cite episode position transcript
    		idcommon = safe_join( { ID_list, URL, Archived, Transcript, AccessDate, Via, Lay, Quote }, sepc );
    	else
    		idcommon = safe_join( { ID_list, URL, Archived, AccessDate, Via, Lay, Quote }, sepc );
    	end
    	
    	local text;
    	local pgtext = Position .. Sheet .. Sheets .. Page .. Pages .. At;
    
    	local OrigDate = A['OrigDate'];
    	OrigDate = utilities.is_set (OrigDate) and wrap_msg ('origdate', OrigDate) or '';
    	if utilities.is_set (Date) then
    		if utilities.is_set (Authors) or utilities.is_set (Editors) then		-- date follows authors or editors when authors not set
    			Date = " (" .. Date .. ")" .. OrigDate .. sepc .. " ";				-- in parentheses
    		else																	-- neither of authors and editors set
    			if (string.sub(tcommon, -1, -1) == sepc) then						-- if the last character of tcommon is sepc
    				Date = " " .. Date .. OrigDate;									-- Date does not begin with sepc
    			else
    				Date = sepc .. " " .. Date .. OrigDate;							-- Date begins with sepc
    			end
    		end
    	end	
    	if utilities.is_set (Authors) then
    		if (not utilities.is_set (Date)) then									-- when date is set it's in parentheses; no Authors termination
    			Authors = terminate_name_list (Authors, sepc);						-- when no date, terminate with 0 or 1 sepc and a space
    		end
    		if utilities.is_set (Editors) then
    			local in_text = " ";
    			local post_text = "";
    			if utilities.is_set (Chapter) and 0 == #c then
    				in_text = in_text .. cfg.messages['in'] .. " "
    				if (sepc ~= '.') then
    					in_text = in_text:lower()									-- lowercase for cs2
    				end
    			end
    			if EditorCount <= 1 then
    				post_text = " (" .. cfg.messages['editor'] .. ")";				-- be consistent with no-author, no-date case
    			else
    				post_text = " (" .. cfg.messages['editors'] .. ")";
    			end
    			Editors = terminate_name_list (in_text .. Editors .. post_text, sepc);	-- terminate with 0 or 1 sepc and a space
    		end
    		if utilities.is_set (Contributors) then									-- book cite and we're citing the intro, preface, etc.
    			local by_text = sepc .. ' ' .. cfg.messages['by'] .. ' ';
    			if (sepc ~= '.') then by_text = by_text:lower() end					-- lowercase for cs2
    			Authors = by_text .. Authors;										-- author follows title so tweak it here
    			if utilities.is_set (Editors) and utilities.is_set (Date) then		-- when Editors make sure that Authors gets terminated
    				Authors = terminate_name_list (Authors, sepc);					-- terminate with 0 or 1 sepc and a space
    			end
    			if (not utilities.is_set (Date)) then								-- when date is set it's in parentheses; no Contributors termination
    				Contributors = terminate_name_list (Contributors, sepc);		-- terminate with 0 or 1 sepc and a space
    			end
    			text = safe_join( {Contributors, Date, Chapter, tcommon, Authors, Place, Editors, tcommon2, pgtext, idcommon }, sepc );
    		else
    			text = safe_join( {Authors, Date, Chapter, Place, Editors, tcommon, pgtext, idcommon }, sepc );
    		end
    	elseif utilities.is_set (Editors) then
    		if utilities.is_set (Date) then
    			if EditorCount <= 1 then
    				Editors = Editors .. ", " .. cfg.messages['editor'];
    			else
    				Editors = Editors .. ", " .. cfg.messages['editors'];
    			end
    		else
    			if EditorCount <= 1 then
    				Editors = Editors .. " (" .. cfg.messages['editor'] .. ")" .. sepc .. " "
    			else
    				Editors = Editors .. " (" .. cfg.messages['editors'] .. ")" .. sepc .. " "
    			end
    		end
    		text = safe_join( {Editors, Date, Chapter, Place, tcommon, pgtext, idcommon}, sepc );
    	else
    		if utilities.in_array (config.CitationClass, {"journal", "citation"}) and utilities.is_set (Periodical) then
    			text = safe_join( {Chapter, Place, tcommon, pgtext, Date, idcommon}, sepc );
    		else
    			text = safe_join( {Chapter, Place, tcommon, Date, pgtext, idcommon}, sepc );
    		end
    	end
    	
    	if utilities.is_set (PostScript) and PostScript ~= sepc then
    		text = safe_join( {text, sepc}, sepc ); 								-- Deals with italics, spaces, etc.
    		text = text:sub(1, -sepc:len() - 1);
    	end	
    	
    	text = safe_join( {text, PostScript}, sepc );
    
    	-- Now enclose the whole thing in a <cite> element
    	local options = {};
    	
    	if utilities.is_set (config.CitationClass) and config.CitationClass ~= "citation" then
    		options.class = string.format ('%s %s %s', 'citation', config.CitationClass, utilities.is_set (Mode) and Mode or 'cs1');	-- class=citation required for blue highlight when used with |ref=
    	else
    		options.class = string.format ('%s %s', 'citation', utilities.is_set (Mode) and Mode or 'cs2');
    	end
    
    	local Ref = A['Ref'];
    	if 'harv' == Ref then														-- need to check this before setting to default
    		utilities.set_message ('maint_ref_harv');								-- add maint cat to identify templates that have this now-extraneous param value
    	elseif not utilities.is_set (Ref) then
    		Ref = 'harv';															-- set as default when not set externally
    	end
    	if 'none' ~= cfg.keywords_xlate[Ref:lower()] then
    		local id = Ref
    		local namelist = {};													-- holds selected contributor, author, editor name list
    		local year = first_set ({Year, anchor_year}, 2);						-- Year first for legacy citations and for YMD dates that require disambiguation
    
    		if #c > 0 then															-- if there is a contributor list
    			namelist = c;														-- select it
    		elseif #a > 0 then														-- or an author list
    			namelist = a;
    		elseif #e > 0 then														-- or an editor list
    			namelist = e;
    		end
    		local citeref_id
    		if #namelist > 0 then													-- if there are names in namelist
    			citeref_id = make_citeref_id (namelist, year);						-- go make the CITEREF anchor
    		else
    			citeref_id = '';													-- unset
    		end
    		if citeref_id == Ref then
    			utilities.set_message ('maint_ref_duplicates_default');
    		end
    		if 'harv' == Ref then
    			id = citeref_id
    		end
    		options.id = id;
    	end
    	
    	if string.len(text:gsub("<span[^>/]*>(.-)</span>", "%1"):gsub("%b<>", "")) <= 2 then	-- remove <span> tags and other HTML-like markup; then get length of what remains
    		z.error_categories = {};
    		text = utilities.set_message ('err_empty_citation');
    		z.message_tail = {};
    	end
    	
    	local render = {};															-- here we collect the final bits for concatenation into the rendered citation
    
    	if utilities.is_set (options.id) then										-- here we wrap the rendered citation in <cite ...>...</cite> tags
    		table.insert (render, utilities.substitute (cfg.presentation['cite-id'], {mw.uri.anchorEncode(options.id), mw.text.nowiki(options.class), text}));	-- when |ref= is set
    	else
    		table.insert (render, utilities.substitute (cfg.presentation['cite'], {mw.text.nowiki(options.class), text}));	-- all other cases
    	end		
    
    	table.insert (render, utilities.substitute (cfg.presentation['ocins'], {OCinSoutput}));	-- append metadata to the citation
    
    	if 0 ~= #z.message_tail then
    		table.insert (render, ' ');
    		for i,v in ipairs( z.message_tail ) do
    			if utilities.is_set (v[1]) then
    				if i == #z.message_tail then
    					table.insert (render, utilities.error_comment ( v[1], v[2] ));
    				else
    					table.insert (render, utilities.error_comment ( v[1] .. "; ", v[2] ));
    				end
    			end
    		end
    	end
    
    	if 0 ~= #z.maintenance_cats then
    		local maint_msgs = {};													-- here we collect all of the maint messages
    		for _, v in ipairs( z.maintenance_cats ) do								-- append maintenance categories
    			local maint = {};													-- here we assemble a maintenence message
    			table.insert (maint, v);											-- maint msg is the category name
    			table.insert (maint, ' (');											-- open the link text
    			table.insert (maint, utilities.substitute (cfg.messages[':cat wikilink'], {v}));	-- add the link
    			table.insert (maint, ')');											-- and close it
    			table.insert (maint_msgs, table.concat (maint));					-- assemble new maint message and add it to the maint_msgs table
    		end
    		table.insert (render, utilities.substitute (cfg.presentation['hidden-maint'], table.concat (maint_msgs, ' ')));	-- wrap the group of maint message with proper presentation and save
    	end
    	
    	if not no_tracking_cats then
    		for _, v in ipairs( z.error_categories ) do								-- append error categories
    			table.insert (render, utilities.substitute (cfg.messages['cat wikilink'], {v}));
    		end
    		for _, v in ipairs( z.maintenance_cats ) do								-- append maintenance categories
    			table.insert (render, utilities.substitute (cfg.messages['cat wikilink'], {v}));
    		end
    		for _, v in ipairs( z.properties_cats ) do								-- append properties categories
    			table.insert (render, utilities.substitute (cfg.messages['cat wikilink'], {v}));
    		end
    	end
    
    	return table.concat (render);	
    end
    
    
    --[[--------------------------< V A L I D A T E >--------------------------------------------------------------
    
    Looks for a parameter's name in one of several whitelists.
    
    Parameters in the whitelist can have three values:
    	true - active, supported parameters
    	false - deprecated, supported parameters
    	nil - unsupported parameters
    	
    ]]
    
    local function validate (name, cite_class, empty)
    	local name = tostring (name);
    	local enum_name;															-- for enumerated parameters, is name with enumerator replaced with '#'
    	local state;
    	local function state_test (state, name)										-- local function to do testing of state values
    		if true == state then return true; end									-- valid actively supported parameter
    		if false == state then
    			if empty then return nil; end										-- empty deprecated parameters are treated as unknowns
    			deprecated_parameter (name);										-- parameter is deprecated but still supported
    			return true;
    		end
    		if 'discouraged' == state then
    			discouraged_parameter (name);										-- parameter is discouraged but still supported
    			return true;
    		end
    		return nil;
    	end		
    
    	if name:find ('#') then														-- # is a cs1|2 reserved character so parameters with # not permitted
    		return nil;
    	end
    
    	if utilities.in_array (cite_class, whitelist.preprint_template_list ) then	-- limited parameter sets allowed for these templates
    		state = whitelist.limited_basic_arguments[name];
    		if true == state_test (state, name) then return true; end
    
    		state = whitelist.preprint_arguments[cite_class][name];					-- look in the parameter-list for the template identified by cite_class
    		if true == state_test (state, name) then return true; end
    
    																				-- limited enumerated parameters list
    		enum_name = name:gsub("%d+", "#" );										-- replace digit(s) with # (last25 becomes last#) (mw.ustring because non-Western 'local' digits)
    		state = whitelist.limited_numbered_arguments[enum_name];
    		if true == state_test (state, name) then return true; end
    
    		return false;															-- not supported because not found or name is set to nil
    	end																			-- end limited parameter-set templates
    
    	if utilities.in_array (cite_class, whitelist.unique_param_template_list) then 	-- experiment for template-specific parameters for templates that accept parameters from the basic argument list
    		state = whitelist.unique_arguments[cite_class][name];					-- look in the template-specific parameter-lists for the template identified by cite_class
    		if true == state_test (state, name) then return true; end
    	end																			-- if here, fall into general validation
    		
    	state = whitelist.basic_arguments[name];									-- all other templates; all normal parameters allowed
    	if true == state_test (state, name) then return true; end
    
    																				-- all enumerated parameters allowed
    	enum_name = name:gsub("%d+", "#" );											-- replace digit(s) with # (last25 becomes last#) (mw.ustring because non-Western 'local' digits)
    	state = whitelist.numbered_arguments[enum_name];
    	if true == state_test (state, name) then return true; end
    
    	return false;																-- not supported because not found or name is set to nil
    end
    
    
    --[=[-------------------------< I N T E R _ W I K I _ C H E C K >----------------------------------------------
    
    check <value> for inter-language interwiki-link markup.  <prefix> must be a MediaWiki-recognized language
    code.  when these values have the form (without leading colon):
    	[[<prefix>:link|label]] return label as plain-text
    	[[<prefix>:link]] return <prefix>:link as plain-text
    
    return value as is else
    
    ]=]
    
    local function inter_wiki_check (parameter, value)
    	local prefix = value:match ('%[%[(%a+):');									-- get an interwiki prefix if one exists
    	local _;
    	
    	if prefix and cfg.inter_wiki_map[prefix:lower()] then						-- if prefix is in the map, needs preceding colon so
    		table.insert( z.message_tail, {utilities.set_message ('err_bad_paramlink', parameter)});	-- emit an error message
    		_, value, _ = utilities.is_wikilink (value);							-- extract label portion from wikilink
    	end
    	return value;
    end
    
    
    --[[--------------------------< M I S S I N G _ P I P E _ C H E C K >------------------------------------------
    
    Look at the contents of a parameter. If the content has a string of characters and digits followed by an equal
    sign, compare the alphanumeric string to the list of cs1|2 parameters.  If found, then the string is possibly a
    parameter that is missing its pipe.  There are two tests made:
    	{{cite ... |title=Title access-date=2016-03-17}}	-- the first parameter has a value and whitespace separates that value from the missing pipe parameter name
    	{{cite ... |title=access-date=2016-03-17}}			-- the first parameter has no value (whitespace after the first = is trimmed by MediaWiki)
    cs1|2 shares some parameter names with XML/HTML attributes: class=, title=, etc.  To prevent false positives XML/HTML
    tags are removed before the search.
    
    If a missing pipe is detected, this function adds the missing pipe maintenance category.
    
    ]]
    
    local function missing_pipe_check (parameter, value)
    	local capture;
    	value = value:gsub ('%b<>', '');											-- remove XML/HTML tags because attributes: class=, title=, etc.
    
    	capture = value:match ('%s+(%a[%w%-]+)%s*=') or value:match ('^(%a[%w%-]+)%s*=');	-- find and categorize parameters with possible missing pipes
    	if capture and validate (capture) then										-- if the capture is a valid parameter name
    		table.insert( z.message_tail, {utilities.set_message ('err_missing_pipe', parameter)});
    	end
    end
    
    
    --[[--------------------------< H A S _ E X T R A N E O U S _ P U N C T >--------------------------------------
    
    look for extraneous terminal punctuation in most parameter values; parameters listed in skip table are not checked
    
    ]]
    
    local function has_extraneous_punc (param, value)
    	if 'number' == type (param) then
    		return;
    	end
    	
    	param = param:gsub ('%d+', '#');											-- enumerated name-list mask params allow terminal punct; normalize 
    	if cfg.punct_skip[param] then
    		return;																	-- parameter name found in the skip table so done
    	end
    	
    	if value:match ('[,;:]$') then
    		utilities.set_message ('maint_extra_punct');							-- has extraneous punctuation; add maint cat
    	end
    end
    
    
    --[[--------------------------< C I T A T I O N >--------------------------------------------------------------
    
    This is used by templates such as {{cite book}} to create the actual citation text.
    
    ]]
    
    local function citation(frame)
    	Frame = frame;																-- save a copy in case we need to display an error message in preview mode
    	local pframe = frame:getParent()
    	local styles;
    	
    	if nil ~= string.find (frame:getTitle(), 'sandbox', 1, true) then			-- did the {{#invoke:}} use sandbox version?
    		cfg = mw.loadData ('Module:Citation/CS1/Configuration/sandbox');		-- load sandbox versions of support modules
    		whitelist = mw.loadData ('Module:Citation/CS1/Whitelist/sandbox');
    		utilities = require ('Module:Citation/CS1/Utilities/sandbox');
    		validation = require ('Module:Citation/CS1/Date_validation/sandbox');
    		identifiers = require ('Module:Citation/CS1/Identifiers/sandbox');
    		metadata = require ('Module:Citation/CS1/COinS/sandbox');
    		styles = 'Module:Citation/CS1/sandbox/styles.css';
    		
    	else																		-- otherwise
    		cfg = mw.loadData ('Module:Citation/CS1/Configuration');				-- load live versions of support modules
    		whitelist = mw.loadData ('Module:Citation/CS1/Whitelist');
    		utilities = require ('Module:Citation/CS1/Utilities');
    		validation = require ('Module:Citation/CS1/Date_validation');
    		identifiers = require ('Module:Citation/CS1/Identifiers');
    		metadata = require ('Module:Citation/CS1/COinS');
    		styles = 'Module:Citation/CS1/styles.css';
    	end
    
    	utilities.set_selected_modules (cfg);										-- so that functions in Utilities can see the selected cfg tables
    	identifiers.set_selected_modules (cfg, utilities);							-- so that functions in Identifiers can see the selected cfg tables and selected Utilities module
    	validation.set_selected_modules (cfg, utilities);							-- so that functions in Date validataion can see selected cfg tables and the selected Utilities module
    	metadata.set_selected_modules (cfg, utilities);								-- so that functions in COinS can see the selected cfg tables and selected Utilities module
    
    	z = utilities.z;															-- table of error and category tables in Module:Citation/CS1/Utilities
    
    	local args = {};															-- table where we store all of the template's arguments
    	local suggestions = {};														-- table where we store suggestions if we need to loadData them
    	local error_text, error_state;
    
    	local config = {};															-- table to store parameters from the module {{#invoke:}}
    	for k, v in pairs( frame.args ) do											-- get parameters from the {{#invoke}} frame
    		config[k] = v;
    	--	args[k] = v;															-- crude debug support that allows us to render a citation from module {{#invoke:}}; skips parameter validation; TODO: keep?
    	end	
    
    	local capture;																-- the single supported capture when matching unknown parameters using patterns
    	local empty_unknowns = {};													-- sequence table to hold empty unknown params for error message listing
    	for k, v in pairs( pframe.args ) do											-- get parameters from the parent (template) frame
    		v = mw.ustring.gsub (v, '^%s*(.-)%s*$', '%1');							-- trim leading/trailing whitespace; when v is only whitespace, becomes empty string
    		if v ~= '' then
    			if ('string' == type (k)) then
    				k = mw.ustring.gsub (k, '%d', cfg.date_names.local_digits);		-- for enumerated parameters, translate 'local' digits to Western 0-9
    			end
    			if not validate( k, config.CitationClass ) then			
    				error_text = "";
    				if type( k ) ~= 'string' then
    					-- exclude empty numbered parameters
    					if v:match("%S+") ~= nil then
    						error_text, error_state = utilities.set_message ( 'err_text_ignored', {v}, true );
    					end
    				elseif validate( k:lower(), config.CitationClass ) then 
    					error_text, error_state = utilities.set_message ( 'err_parameter_ignored_suggest', {k, k:lower()}, true );	-- suggest the lowercase version of the parameter
    				else
    					if nil == suggestions.suggestions then						-- if this table is nil then we need to load it
    						if nil ~= string.find (frame:getTitle(), 'sandbox', 1, true) then			-- did the {{#invoke:}} use sandbox version?
    							suggestions = mw.loadData( 'Module:Citation/CS1/Suggestions/sandbox' );	-- use the sandbox version
    						else
    							suggestions = mw.loadData( 'Module:Citation/CS1/Suggestions' );			-- use the live version
    						end
    					end
    					for pattern, param in pairs (suggestions.patterns) do		-- loop through the patterns to see if we can suggest a proper parameter
    						capture = k:match (pattern);							-- the whole match if no capture in pattern else the capture if a match
    						if capture then											-- if the pattern matches 
    							param = utilities.substitute (param, capture);		-- add the capture to the suggested parameter (typically the enumerator)
    							if validate (param, config.CitationClass) then		-- validate the suggestion to make sure that the suggestion is supported by this template (necessary for limited parameter lists)
    								error_text, error_state = utilities.set_message ('err_parameter_ignored_suggest', {k, param}, true);	-- set the suggestion error message
    							else
    								error_text, error_state = utilities.set_message ( 'err_parameter_ignored', {k}, true );	-- suggested param not supported by this template
    								v = '';											-- unset
    							end
    						end
    					end
    					if not utilities.is_set (error_text) then					-- couldn't match with a pattern, is there an explicit suggestion?						
    						if (suggestions.suggestions[ k:lower() ] ~= nil) and validate (suggestions.suggestions[ k:lower() ], config.CitationClass) then
    							error_text, error_state = utilities.set_message ( 'err_parameter_ignored_suggest', {k, suggestions.suggestions[ k:lower() ]}, true );
    						else
    							error_text, error_state = utilities.set_message ( 'err_parameter_ignored', {k}, true );
    							v = '';												-- unset value assigned to unrecognized parameters (this for the limited parameter lists)
    						end
    					end
    				end				  
    				if error_text ~= '' then
    					table.insert( z.message_tail, {error_text, error_state} );
    				end				
    			end
    
    			args[k] = v;														-- save this parameter and its value
    
    		elseif not utilities.is_set (v) then									-- for empty parameters
    			if not validate (k, config.CitationClass, true) then				-- is this empty parameter a valid parameter
    				k = ('' == k) and '(empty string)' or k;						-- when k is empty string (or was space(s) trimmed to empty string), replace with descriptive text
    				table.insert (empty_unknowns, utilities.wrap_style ('parameter', k));	-- format for error message and add to the list
    			end
    																				-- crude debug support that allows us to render a citation from module {{#invoke:}} TODO: keep?
    	--	elseif args[k] ~= nil or (k == 'postscript') then						-- when args[k] has a value from {{#invoke}} frame (we don't normally do that)
    	--		args[k] = v;														-- overwrite args[k] with empty string from pframe.args[k] (template frame); v is empty string here
    		end																		-- not sure about the postscript bit; that gets handled in parameter validation; historical artifact?
    	end	
    
    	if 0 ~= #empty_unknowns then												-- create empty unknown error message
    		table.insert (z.message_tail, {utilities.set_message ('err_param_unknown_empty', {
    			1 == #empty_unknowns and '' or 's',
    			utilities.make_sep_list (#empty_unknowns, empty_unknowns)
    			}, true )});
    	end
    
    	for k, v in pairs( args ) do
    		if 'string' == type (k) then											-- don't evaluate positional parameters
    			has_invisible_chars (k, v);											-- look for invisible characters
    		end
    		has_extraneous_punc (k, v);												-- look for extraneous terminal punctuation in parameter values
    		missing_pipe_check (k, v);												-- do we think that there is a parameter that is missing a pipe?
    		args[k] = inter_wiki_check (k, v);										-- when language interwiki-linked parameter missing leading colon replace with wiki-link label
    	end
    
    	return table.concat ({
    		frame:extensionTag ('templatestyles', '', {src=styles}),
    		citation0( config, args)
    	});
    end
    
    --[[--------------------------< E X P O R T E D   F U N C T I O N S >------------------------------------------
    ]]
    
    return {citation = citation};