Module:Citation/CS1: Difference between revisions

    m>Trappist the monk
    (bug fix in page number rendering (NoPP);)
    m>Trappist the monk
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    --[[--------------------------< F I R S T _ S E T >------------------------------------------------------------
    --[[--------------------------< F I R S T _ S E T >------------------------------------------------------------


    First set variable or nil if none
    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(...)
    local function first_set (list, count)
    local list = {...};
    local i = 1;
    for _, var in pairs(list) do
    while i <= count do -- loop through all items in list
    if is_set( var ) then
    if is_set( list[i] ) then
    return var;
    return list[i]; -- return the first set list member
    end
    end
    i = i + 1; -- point to next
    end
    end
    end
    end
    Line 160: Line 166:
    end
    end


    --[[--------------------------< C H E C K _ U R L >------------------------------------------------------------


    Determines whether a URL string is valid.
    --[[--------------------------< I S _ S C H E M E >------------------------------------------------------------


    At present the only check is whether the string appears to be prefixed with a URI scheme. It is not determined whether
    does this thing that purports to be a uri scheme seem to be a valid scheme? The scheme is checked to see if it
    the URI scheme is valid or whether the URL is otherwise well formed.
    is in agreement with http://tools.ietf.org/html/std66#section-3.1 which says:
     
    The scheme is checked http://tools.ietf.org/html/std66#section-3.1 which says:
    Scheme names consist of a sequence of characters beginning with a
    Scheme names consist of a sequence of characters beginning with a
       letter and followed by any combination of letters, digits, plus
       letter and followed by any combination of letters, digits, plus
       ("+"), period ("."), or hyphen ("-").
       ("+"), period ("."), or hyphen ("-").


    First we test for space characters.  If any are found, return false.  Then test for the case where the url is
    returns true if it does, else false
    protocol relative (//example.com).  If the first two characters of the |url= value are //, return true.  Last
     
    look for what appears to be a scheme according to the definition above.  If the characters preceding the colon
    are in the allowed set, return true, else false
    ]]
    ]]


    local function check_url( url_str )
    local function is_scheme (scheme)
    if nil == url_str:match ("^%S+$") then -- if there are any spaces in |url=value
    return scheme and scheme:match ('^%a[%a%d%+%.%-]*:'); -- true if scheme is set and matches the pattern
    return false;
    end
    return url_str:sub(1,2) == "//" or nil ~= url_str:match ("^%a[%a%d%+%.%-]*:") -- protocol relative or scheme part composed of legitimate characters
    end
    end


    --[[--------------------------< S A F E _ F O R _ I T A L I C S >----------------------------------------------


    Protects a string that will be wrapped in wiki italic markup '' ... ''
    --[[--------------------------< 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?
     
    rfc952 (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. Single character names are not allowed.
     
    Also allowed are IPv4 addresses. IPv6 not supported
     
    There are three tests: the first is looking for a hostname that is 2 to n letters or digits followed by a dot and a
    letter (tld); the second looks for a hostname that is 3 to n characters where the first and last are letters or
    digits and the middle characters are letters, digits, or the hyphen; the whole followed by a dot and a letter or digit.
    The third test is for IPv4 dot-decimal address format; tld not allowed.


    Note: We cannot use <i> for italics, as the expected behavior for italics specified by ''...'' in the title is that
    returns true if domain appears to be a proper name and tld or IPv4 address, else false
    they will be inverted (i.e. unitalicized) in the resulting references.  In addition, <i> and '' tend to interact
    poorly under Mediawiki's HTML tidy.


    ]]
    ]]


    local function safe_for_italics( str )
    local function is_domain_name (domain)
    if not is_set(str) then
    if not domain then
    return str;
    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 domain:match ('^[%a%d][%a%d]+%.%a') then -- two character hostname and tld
    return true;
    elseif domain:match ('^[%a%d][%a%d%-]+[%a%d]%.[%a%d]') then -- three or more character hostname.hostname or hostname.tld
    return true;
    elseif domain:match ('^%d%d?%d?%.%d%d?%d?%.%d%d?%d?%.%d%d?%d?') then -- IPv4 address
    return true;
    else
    else
    if str:sub(1,1) == "'" then str = "<span />" .. str; end
    return false;
    if str:sub(-1,-1) == "'" then str = str .. "<span />"; end
    -- Remove newlines as they break italics.
    return str:gsub( '\n', ' ' );
    end
    end
    end
    end


    --[[--------------------------< S A F E _ F O R _ U R L >------------------------------------------------------


    Escape sequences for content that will be used for URL descriptions
    --[[--------------------------< 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 safe_for_url( str )
    local function is_url (scheme, domain)
    if str:match( "%[%[.-%]%]" ) ~= nil then  
    if is_set (scheme) then -- if scheme is set check it and domain
    table.insert( z.message_tail, { set_error( 'wikilink_in_url', {}, true ) } );
    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 and domain pair and return both parts.  If protocol relative url, return nil for scheme
    and domain else return nil for both scheme and domain.
     
    ]]
     
    local function split_url (url_str)
    local scheme, domain;
    if url_str:match ('%S-:%S+') then -- if there is what appears to be a scheme domain pair
    scheme, domain = url_str:match ('(%S-:)(%S+)'); -- extract the scheme and domain portions
    elseif url_str:match ('//%S*') then -- if there is what appears to be a protocol relative url
    domain = url_str:match ('//(%S*)')
    end
    end
    return str:gsub( '[%[%]\n]', {
    return scheme, domain;
    ['['] = '&#91;',
    [']'] = '&#93;',
    ['\n'] = ' ' } );
    end
    end


    --[[--------------------------< W R A P _ S T Y L E >----------------------------------------------------------


    Applies styling to various parameters.  Supplied string is wrapped using a message_list configuration taking one
    --[[--------------------------< L I N K _ P A R A M _ O K >---------------------------------------------------
    argument; protects italic styled parameters. Additional text taken from citation_config.presentation - the reason
     
    this function is similar to but separate from wrap_msg().
    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:
    # < > [ ] | { } _
    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 wrap_style (key, str)
    local function link_param_ok (value)
    if not is_set( str ) then
    local scheme, domain;
    return "";
    if value:find ('[#<>%[%]|{}_]') then -- if any prohibited characters
    elseif in_array( key, { 'italic-title', 'trans-italic-title' } ) then
    return false;
    str = safe_for_italics( str );
    end
    end


    return substitute( cfg.presentation[key], {str} );
    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
    end


    --[[--------------------------< E X T E R N A L _ L I N K >----------------------------------------------------


    Format an external link with error checking
    --[[--------------------------< 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_scheme() and is_domain() to
    validate the two portions of the url.  If both are valid, or for protocol relative if domain is valid, return true, else false.


    ]]
    ]]


    local function external_link( URL, label, source )
    local function check_url( url_str )
    local error_str = "";
    if nil == url_str:match ("^%S+$") then -- if there are any spaces in |url=value it can't be a proper url
    if not is_set( label ) then
    return false;
    label = URL;
    end
    if is_set( source ) then
    local scheme, domain;
    error_str = set_error( 'bare_url_missing_title', { wrap_style ('parameter', source) }, false, " " );
     
    else
    scheme, domain = split_url (url_str); -- get scheme or nil and domain or nil from url;
    error( cfg.messages["bare_url_no_origin"] );
    return is_url (scheme, domain); -- return true if value appears to be a valid url
    end
    end
    if not check_url( URL ) then
    error_str = set_error( 'bad_url', {}, false, " " ) .. error_str;
    end
    return table.concat({ "[", URL, " ", safe_for_url( label ), "]", error_str });
    end
    end


    --[[--------------------------< E X T E R N A L _ L I N K _ I D >----------------------------------------------


    Formats a wiki style external link
    --[=[-------------------------< 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
    characters following the opening bracket obey the rules of a uri scheme (see check_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=, and
    |work=) 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;


    local function external_link_id(options)
    if value:match ('%f[%[]%[%a%S*:%S.*%]') then -- if ext wikilink with scheme and domain: [xxxx://yyyyy.zzz]
    local url_string = options.id;
    scheme, domain = value:match ('%f[%[]%[(%a%S*:)(%S.*)%]')
    if options.encode == true or options.encode == nil then
    elseif value:match ('%f[%[]%[//%S*%.%S*%]') then -- if protocol relative ext wikilink: [//yyyyy.zzz]
    url_string = mw.uri.encode( url_string );
    domain = value:match ('%f[%[]%[//(%S*%.%S*)%]');
    else
    scheme, domain = split_url (value); -- get scheme or nil and domain or nil from url;  
    end
    end
    return mw.ustring.format( '[[%s|%s]]%s[%s%s%s %s]',
     
    options.link, options.label, options.separator or "&nbsp;",
    return is_url (scheme, domain); -- return true if value appears to be a valid url
    options.prefix, url_string, options.suffix or "",
    mw.text.nowiki(options.id)
    );
    end
    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 parametersThe function includes the
    --[[-------------------------< C H E C K _ F O R _ U R L >-----------------------------------------------------
    offending parameter name to the error message.  Only one error message is emitted regardless of the number of deprecated
     
    parameters in the citation.
    loop through a list of parameters and their valuesLook at the value and if it has an external link, emit an error message.


    ]]
    ]]


    local page_in_deprecated_cat; -- sticky flag so that the category is added only once
    local function check_for_url (parameter_list)
    local function deprecated_parameter(name)
    local error_message = '';
    if not page_in_deprecated_cat then
    for k, v in pairs (parameter_list) do -- for each parameter in the list
    page_in_deprecated_cat = true; -- note that we've added this category
    if is_parameter_ext_wikilink (v) then -- look at the value; if there is a url add an error message
    table.insert( z.message_tail, { set_error( 'deprecated_params', {name}, true ) } ); -- add error message
    if 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 is_set (error_message) then -- done looping, if there is an error message, display it
    table.insert( z.message_tail, { set_error( 'param_has_ext_link', {error_message}, true ) } );
    end
    end
    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.
    --[[--------------------------< S A F E _ F O R _ I T A L I C S >----------------------------------------------
    This function will positive kern either single or double quotes:
     
    "'Unkerned title with leading and trailing single quote marks'"
    Protects a string that will be wrapped in wiki italic markup '' ... ''
    " '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 wikimarkup) are not kerned.


    Call this function for chapter titles, for website titles, etc; not for book titles.
    Note: We cannot use <i> for italics, as the expected behavior for italics specified by ''...'' in the title is that
    they will be inverted (i.e. unitalicized) in the resulting references.  In addition, <i> and '' tend to interact
    poorly under Mediawiki's HTML tidy.


    ]]
    ]]


    local function kern_quotes (str)
    local function safe_for_italics( str )
    local cap='';
    if not is_set(str) then
    local cap2='';
    return str;
    else
    cap, cap2 = str:match ("^([\"\'])([^\'].+)"); -- match leading double or single quote but not double single quotes
    if str:sub(1,1) == "'" then str = "<span />" .. str; end
    if is_set (cap) then
    if str:sub(-1,-1) == "'" then str = str .. "<span />"; end
    str = substitute (cfg.presentation['kern-left'], {cap, cap2});
    -- Remove newlines as they break italics.
    return str:gsub( '\n', ' ' );
    end
    end
    end


    cap, cap2 = str:match ("^(.+[^\'])([\"\'])$")
    --[[--------------------------< S A F E _ F O R _ U R L >------------------------------------------------------
    if is_set (cap) then
     
    str = substitute (cfg.presentation['kern-right'], {cap, cap2});
    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, { set_error( 'wikilink_in_url', {}, true ) } );
    end
    end
    return str;
    return str:gsub( '[%[%]\n]', {
    ['['] = '&#91;',
    [']'] = '&#93;',
    ['\n'] = ' ' } );
    end
    end


    --[[--------------------------< F O R M A T _ S C R I P T _ V A L U E >----------------------------------------
    --[[--------------------------< W R A P _ S T Y L E >----------------------------------------------------------


    |script-title= holds title parameters that are not written in Latin based scripts: Chinese, Japanese, Arabic, Hebrew, etc. These scripts should
    Applies styling to various parameters. Supplied string is wrapped using a message_list configuration taking one
    not be italicized and may be written right-to-leftThe value supplied by |script-title= is concatenated onto Title after Title has been wrapped
    argument; protects italic styled parametersAdditional text taken from citation_config.presentation - the reason
    in italic markup.
    this function is similar to but separate from wrap_msg().


    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.
    ]]
     
    local function wrap_style (key, str)
    if not is_set( str ) then
    return "";
    elseif in_array( key, { 'italic-title', 'trans-italic-title' } ) then
    str = safe_for_italics( str );
    end


    |script-title= provides a unique feature.  The value in |script-title= may be prefixed with a two-character ISO639-1 language code and a colon:
    return substitute( cfg.presentation[key], {str} );
    |script-title=ja:*** *** (where * represents a Japanese character)
    end
    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 ISO639-1 language code, the lang attribute (lang="ja") is added to the <bdi> tag so that browsers can
    --[[--------------------------< E X T E R N A L _ L I N K >----------------------------------------------------
    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= and |script-chapter=
    Format an external link with error checking


    TODO: error messages when prefix is invalid ISO639-1 code; when script_value has prefix but no script;
    ]]
    ]]


    local function format_script_value (script_value)
    local function external_link( URL, label, source )
    local lang=''; -- initialize to empty string
    local error_str = "";
    local name;
    if not is_set( label ) then
    if script_value:match('^%l%l%s*:') then -- if first 3 non-space characters are script language prefix
    label = URL;
    lang = script_value:match('^(%l%l)%s*:%s*%S.*'); -- get the language prefix or nil if there is no script
    if is_set( source ) then
    if not is_set (lang) then
    error_str = set_error( 'bare_url_missing_title', { wrap_style ('parameter', source) }, false, " " );
    return ''; -- script_value was just the prefix so return empty string
    else
    end
    error( cfg.messages["bare_url_no_origin"] );
    -- if we get this far we have prefix and script
    end
    name = mw.language.fetchLanguageName( lang, "en" ); -- get language name so that we can use it to categorize
    end
    if is_set (name) then -- is prefix a proper ISO 639-1 language code?
    if not check_url( URL ) then
    script_value = script_value:gsub ('^%l%l%s*:%s*', ''); -- strip prefix from script
    error_str = set_error( 'bad_url', {wrap_style ('parameter', source)}, false, " " ) .. error_str;
    -- is prefix one of these language codes?
    if in_array (lang, {'ar', 'bg', 'bs', 'dv', 'el', 'fa', 'he', 'hy', 'ja', 'ka', 'ko', 'ku', 'mk', 'ps', 'ru', 'sd', 'sr', 'th', 'uk', 'ug', 'yi', 'zh'}) then
    add_prop_cat ('script_with_name', {name, lang})
    else
    add_prop_cat ('script')
    end
    lang = ' lang="' .. lang .. '" '; -- convert prefix into a lang attribute
    else
    lang = ''; -- invalid so set lang to empty string
    end
    end
    end
    script_value = substitute (cfg.presentation['bdi'], {lang, script_value}); -- isolate in case script is rtl
    return table.concat({ "[", URL, " ", safe_for_url( label ), "]", error_str });
    end


    return script_value;
    --[[--------------------------< E X T E R N A L _ L I N K _ I D >----------------------------------------------
    end


    --[[--------------------------< S C R I P T _ C O N C A T E N A T E >------------------------------------------
    Formats a wiki style external link


    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)
    local function external_link_id(options)
    if is_set (script) then
    local url_string = options.id;
    script = format_script_value (script); -- <bdi> tags, lang atribute, categorization, etc; returns empty string on error
    if options.encode == true or options.encode == nil then
    if is_set (script) then
    url_string = mw.uri.encode( url_string );
    title = title .. ' ' .. script; -- concatenate title and script title
    end
    end
    return mw.ustring.format( '[[%s|%s]]%s[%s%s%s %s]',
    end
    options.link, options.label, options.separator or "&nbsp;",
    return title;
    options.prefix, url_string, options.suffix or "",
    mw.text.nowiki(options.id)
    );
    end
    end


    --[[--------------------------< D E P R E C A T E D _ P A R A M E T E R >--------------------------------------


    --[[--------------------------< W R A P _ M S G >--------------------------------------------------------------
    Categorize and emit an error message when the citation contains one or more deprecated parametersThe function includes the
     
    offending parameter name to the error messageOnly one error message is emitted regardless of the number of deprecated
    Applies additional message text to various parameter values. Supplied string is wrapped using a message_list
    parameters in the citation.
    configuration taking one argumentSupports lower case text for {{citation}} templatesAdditional 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)
    local page_in_deprecated_cat; -- sticky flag so that the category is added only once
    if not is_set( str ) then
    local function deprecated_parameter(name)
    return "";
    if not page_in_deprecated_cat then
    page_in_deprecated_cat = true; -- note that we've added this category
    table.insert( z.message_tail, { set_error( 'deprecated_params', {name}, true ) } ); -- add error message
    end
    end
    if true == lower then
    local msg;
    msg = cfg.messages[key]:lower(); -- set the message to lower case before
    str = substitute( msg, {str} ); -- including template text
    return str;
    else
    return substitute( cfg.messages[key], {str} );
    end
    end
    end


    --[[--------------------------< S E L E C T _ O N E >----------------------------------------------------------
    --[[--------------------------< K E R N _ Q U O T E S >--------------------------------------------------------
     
     
    Chooses one matching parameter from a list of parameters to consider
    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.
    Generates an error if more than one match is present.
    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 wikimarkup) are not kerned.
     
    Call this function for chapter titles, for website titles, etc; not for book titles.


    ]]
    ]]


    local function select_one( args, possible, error_condition, index )
    local function kern_quotes (str)
    local value = nil;
    local cap='';
    local selected = '';
    local cap2='';
    local error_list = {};
    if index ~= nil then index = tostring(index); end
    cap, cap2 = str:match ("^([\"\'])([^\'].+)"); -- match leading double or single quote but not double single quotes
    if is_set (cap) then
    -- Handle special case of "#" replaced by empty string
    str = substitute (cfg.presentation['kern-left'], {cap, cap2});
    if index == '1' then
    for _, v in ipairs( possible ) do
    v = v:gsub( "#", "" );
    if is_set(args[v]) then
    if value ~= nil and selected ~= v then
    table.insert( error_list, v );
    else
    value = args[v];
    selected = v;
    end
    end
    end
    end
    end
     
    for _, v in ipairs( possible ) do
    cap, cap2 = str:match ("^(.+[^\'])([\"\'])$")
    if index ~= nil then
    if is_set (cap) then
    v = v:gsub( "#", index );
    str = substitute (cfg.presentation['kern-right'], {cap, cap2});
    end
    if is_set(args[v]) then
    if value ~= nil and selected ~=  v then
    table.insert( error_list, v );
    else
    value = args[v];
    selected = v;
    end
    end
    end
    end
    return str;
    if #error_list > 0 then
    end
    local error_str = "";
     
    for _, k in ipairs( error_list ) do
    --[[--------------------------< F O R M A T _ S C R I P T _ V A L U E >----------------------------------------
    if error_str ~= "" then error_str = error_str .. cfg.messages['parameter-separator'] end
     
    error_str = error_str .. wrap_style ('parameter', k);
    |script-title= holds title parameters that are not written in Latin based scripts: Chinese, Japanese, Arabic, Hebrew, etc. These scripts should
    end
    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
    if #error_list > 1 then
    in italic markup.
    error_str = error_str .. cfg.messages['parameter-final-separator'];
     
    else
    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.
    error_str = error_str .. cfg.messages['parameter-pair-separator'];
     
    end
    |script-title= provides a unique feature. The value in |script-title= may be prefixed with a two-character ISO639-1 language code and a colon:
    error_str = error_str .. wrap_style ('parameter', selected);
    |script-title=ja:*** *** (where * represents a Japanese character)
    table.insert( z.message_tail, { set_error( error_condition, {error_str}, true ) } );
    Spaces between the two-character code and the colon and the colon and the first script character are allowed:
    end
    |script-title=ja : *** ***
    |script-title=ja: *** ***
    return value, selected;
    |script-title=ja :*** ***
    end
    Spaces preceding the prefix are allowed: |script-title = ja:*** ***


    --[[--------------------------< F O R M A T _ C H A P T E R _ T I T L E >--------------------------------------
    The prefix is checked for validity.  If it is a valid ISO639-1 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.


    Format the four chapter parameters: |script-chapter=, |chapter=, |trans-chapter=, and |chapter-url= into a single Chapter meta-
    Supports |script-title= and |script-chapter=
    parameter (chapter_url_source used for error messages).


    TODO: error messages when prefix is invalid ISO639-1 code; when script_value has prefix but no script;
    ]]
    ]]


    local function format_chapter_title (scriptchapter, chapter, transchapter, chapterurl, chapter_url_source)
    local function format_script_value (script_value)
    local chapter_error = '';
    local lang=''; -- initialize to empty string
    local name;
    if not is_set (chapter) then
    if script_value:match('^%l%l%s*:') then -- if first 3 non-space characters are script language prefix
    chapter = ''; -- to be safe for concatenation
    lang = script_value:match('^(%l%l)%s*:%s*%S.*'); -- get the language prefix or nil if there is no script
    else
    if not is_set (lang) then
    chapter = kern_quotes (chapter); -- if necessary, separate chapter title's leading and trailing quote marks from Module provided quote marks
    return ''; -- script_value was just the prefix so return empty string
    chapter = wrap_style ('quoted-title', chapter);
    end
    -- if we get this far we have prefix and script
    name = mw.language.fetchLanguageName( lang, "en" ); -- get language name so that we can use it to categorize
    if is_set (name) then -- is prefix a proper ISO 639-1 language code?
    script_value = script_value:gsub ('^%l%l%s*:%s*', ''); -- strip prefix from script
    -- is prefix one of these language codes?
    if in_array (lang, {'ar', 'bg', 'bs', 'dv', 'el', 'fa', 'he', 'hy', 'ja', 'ka', 'ko', 'ku', 'mk', 'ps', 'ru', 'sd', 'sr', 'th', 'uk', 'ug', 'yi', 'zh'}) then
    add_prop_cat ('script_with_name', {name, lang})
    else
    add_prop_cat ('script')
    end
    lang = ' lang="' .. lang .. '" '; -- convert prefix into a lang attribute
    else
    lang = ''; -- invalid so set lang to empty string
    end
    end
    end
    script_value = substitute (cfg.presentation['bdi'], {lang, script_value}); -- isolate in case script is rtl


    chapter = script_concatenate (chapter, scriptchapter) -- <bdi> tags, lang atribute, categorization, etc; must be done after title is wrapped
    return script_value;
    end


    if is_set (transchapter) then
    --[[--------------------------< S C R I P T _ C O N C A T E N A T E >------------------------------------------
    transchapter = wrap_style ('trans-quoted-title', transchapter);
    if is_set (chapter) then
    chapter = chapter ..  ' ' .. transchapter;
    else -- here when transchapter without chapter or script-chapter
    chapter = transchapter; --  
    chapter_error = ' ' .. set_error ('trans_missing_title', {'chapter'});
    end
    end


    if is_set (chapterurl) then
    Initially for |title= and |script-title=, this function concatenates those two parameter values after the script value has been
    chapter = external_link (chapterurl, chapter, chapter_url_source); -- adds bare_url_missing_title error if appropriate
    wrapped in <bdi> tags.
    ]]
     
    local function script_concatenate (title, script)
    if is_set (script) then
    script = format_script_value (script); -- <bdi> tags, lang atribute, categorization, etc; returns empty string on error
    if is_set (script) then
    title = title .. ' ' .. script; -- concatenate title and script title
    end
    end
    end
    return title;
    end


    return chapter .. chapter_error;
    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().


    --[[
    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 function wrap_msg (key, str, lower)
    local origin = {};
    if not is_set( str ) then
    return "";
    return setmetatable({
    end
    ORIGIN = function( self, k )
    if true == lower then
    local dummy = self[k]; --force the variable to be loaded.
    local msg;
    return origin[k];
    msg = cfg.messages[key]:lower(); -- set the message to lower case before
    end
    return substitute( msg, str ); -- including template text
    },
    else
    {
    return substitute( cfg.messages[key], str );
    __index = function ( tbl, k )
    end
    if origin[k] ~= nil then
    return nil;
    end
    local args, list, v = args, cfg.aliases[k];
    if type( list ) == 'table' then
    v, origin[k] = select_one( args, list, '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'] );
    end
    -- Empty strings, not nil;
    if v == nil then
    v = cfg.defaults[k] or '';
    origin[k] = '';
    end
    tbl = rawset( tbl, k, v );
    return v;
    end,
    });
    end
    end


    --[[
    Looks for a parameter's name in the whitelist.


    Parameters in the whitelist can have three values:
    --[[-------------------------< I S _ A L I A S _ U S E D >-----------------------------------------------------
    true - active, supported parameters
     
    false - deprecated, supported parameters
    This function is used by select_one() to determine if one of a list of alias parameters is in the argument list
    nil - unsupported parameters
    provided by the template.
     
    Input:
    args – pointer to the arguments table from calling template
    alias – one of the list of possible aliases in the aliases lists from Module:Citation/CS1/Configuration
    index – for enumerated parameters, identifies which one
    enumerated – true/false flag used choose how enumerated aliases are examined
    value – value associated with an alias that has previously been selected; nil if not yet selected
    selected – the alias that has previously been selected; nil if not yet selected
    error_list – list of aliases that are duplicates of the alias already selected
     
    Returns:
    value – value associated with alias we selected or that was previously selected or nil if an alias not yet selected
    selected – the alias we selected or the alias that was previously selected or nil if an alias not yet selected
     
    ]]
    ]]


    local function validate( name )
    local function is_alias_used (args, alias, index, enumerated, value, selected, error_list)
    local name = tostring( name );
    if enumerated then -- is this a test for an enumerated parameters?
    local state = whitelist.basic_arguments[ name ];
    alias = alias:gsub ('#', index); -- replace '#' with the value in index
    else
    -- Normal arguments
    alias = alias:gsub ('#', ''); -- remove '#' if it exists
    if true == state then return true; end -- valid actively supported parameter
    if false == state then
    deprecated_parameter (name); -- parameter is deprecated but still supported
    return true;
    end
    end
     
    -- Arguments with numbers in them
    if is_set(args[alias]) then -- alias is in the template's argument list
    name = name:gsub( "%d+", "#" ); -- replace digit(s) with # (last25 becomes last#
    if value ~= nil and selected ~= alias then -- if we have already selected one of the aliases
    state = whitelist.numbered_arguments[ name ];
    local skip;
    if true == state then return true; end -- valid actively supported parameter
    for _, v in ipairs(error_list) do -- spin through the error list to see if we've added this alias
    if false == state then
    if v == alias then
    deprecated_parameter (name); -- parameter is deprecated but still supported
    skip = true;
    return true;
    break; -- has been added so stop looking
    end
    end
    if not skip then -- has not been added so
    table.insert( error_list, alias ); -- add error alias to the error list
    end
    else
    value = args[alias]; -- not yet selected an alias, so select this one
    selected = alias;
    end
    end
    end
    return value, selected; -- return newly selected alias, or previously selected alias
    return false; -- Not supported because not found or name is set to nil
    end
    end




    -- Formats a wiki style internal link
    --[[--------------------------< S E L E C T _ O N E >----------------------------------------------------------
    local function internal_link_id(options)
     
    return mw.ustring.format( '[[%s|%s]]%s[[%s%s%s|%s]]',
    Chooses one matching parameter from a list of parameters to consider. The list of parameters to consider is just
    options.link, options.label, options.separator or "&nbsp;",
    names. For parameters that may be enumerated, the position of the numerator in the parameter name is identified
    options.prefix, options.id, options.suffix or "",
    by the '#' so |author-last1= and |author1-last= are represented as 'author-last#' and 'author#-last'.
    mw.text.nowiki(options.id)
     
    );
    Because enumerated parameter |<param>1= is an alias of |<param>= we must test for both possibilities.
    end




    --[[--------------------------< N O W R A P _ D A T E >--------------------------------------------------------
    Generates an error if more than one match is present.


    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 select_one( args, aliases_list, error_condition, index )
    local value = nil; -- the value assigned to the selected parameter
    local selected = ''; -- the name of the parameter we have chosen
    local error_list = {};


    ]]
    if index ~= nil then index = tostring(index); end


    local function nowrap_date (date)
    for _, alias in ipairs( aliases_list ) do -- for each alias in the aliases list
    local cap='';
    if alias:match ('#') then -- if this alias can be enumerated
    local cap2='';
    if '1' == index then -- when index is 1 test for enumerated and non-enumerated aliases
    value, selected = is_alias_used (args, alias, index, false, value, selected, error_list); -- first test for non-enumerated alias
    end
    value, selected = is_alias_used (args, alias, index, true, value, selected, error_list); -- test for enumerated alias
    else
    value, selected = is_alias_used (args, alias, index, false, value, selected, error_list); --test for non-enumerated alias
    end
    end


    if date:match("^%d%d%d%d%-%d%d%-%d%d$") then
    if #error_list > 0 and 'none' ~= error_condition then -- for cases where this code is used outside of extract_names()
    date = substitute (cfg.presentation['nowrap1'], date);
    local error_str = "";
    for _, k in ipairs( error_list ) do
    elseif date:match("^%a+%s*%d%d?,%s*%d%d%d%d$") or date:match ("^%d%d?%s*%a+%s*%d%d%d%d$") then
    if error_str ~= "" then error_str = error_str .. cfg.messages['parameter-separator'] end
    cap, cap2 = string.match (date, "^(.*)%s+(%d%d%d%d)$");
    error_str = error_str .. wrap_style ('parameter', k);
    date = substitute (cfg.presentation['nowrap2'], {cap, cap2});
    end
    if #error_list > 1 then
    error_str = error_str .. cfg.messages['parameter-final-separator'];
    else
    error_str = error_str .. cfg.messages['parameter-pair-separator'];
    end
    error_str = error_str .. wrap_style ('parameter', selected);
    table.insert( z.message_tail, { set_error( error_condition, {error_str}, true ) } );
    end
    end
    return date;
    return value, selected;
    end
    end


    --[[--------------------------< IS _ V A L I D _ I S X N >-----------------------------------------------------


    ISBN-10 and ISSN validator code calculates checksum across all isbn/issn digits including the check digit. ISBN-13 is checked in check_isbn().
    --[[--------------------------< F O R M A T _ C H A P T E R _ T I T L E >--------------------------------------
    If the number is valid the result will be 0. Before calling this function, issbn/issn must be checked for length and stripped of dashes,
     
    spaces and other non-isxn characters.
    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 is_valid_isxn (isxn_str, len)
    local function format_chapter_title (scriptchapter, chapter, transchapter, chapterurl, chapter_url_source, no_quotes)
    local temp = 0;
    local chapter_error = '';
    isxn_str = { isxn_str:byte(1, len) }; -- make a table of byte values '0' → 0x30 .. '9'  → 0x39, 'X' → 0x58
    len = len+1; -- adjust to be a loop counter
    if not is_set (chapter) then
    for i, v in ipairs( isxn_str ) do -- loop through all of the bytes and calculate the checksum
    chapter = ''; -- to be safe for concatenation
    if v == string.byte( "X" ) then -- if checkdigit is X (compares the byte value of 'X' which is 0x58)
    else
    temp = temp + 10*( len - i ); -- it represents 10 decimal
    if false == no_quotes then
    else
    chapter = kern_quotes (chapter); -- if necessary, separate chapter title's leading and trailing quote marks from Module provided quote marks
    temp = temp + tonumber( string.char(v) )*(len-i);
    chapter = wrap_style ('quoted-title', chapter);
    end
    end
    end
    end
    return temp % 11 == 0; -- returns true if calculation result is zero
    end


    chapter = script_concatenate (chapter, scriptchapter) -- <bdi> tags, lang atribute, categorization, etc; must be done after title is wrapped


    --[[--------------------------< IS _ V A L I D _ I S X N _ 1 3 >----------------------------------------------
    if is_set (transchapter) then
    transchapter = wrap_style ('trans-quoted-title', transchapter);
    if is_set (chapter) then
    chapter = chapter .. ' ' .. transchapter;
    else -- here when transchapter without chapter or script-chapter
    chapter = transchapter; --  
    chapter_error = ' ' .. set_error ('trans_missing_title', {'chapter'});
    end
    end


    ISBN-13 and ISMN validator code calculates checksum across all 13 isbn/ismn digits including the check digit.
    if is_set (chapterurl) then
    If the number is valid, the result will be 0. Before calling this function, isbn-13/ismn must be checked for length
    chapter = external_link (chapterurl, chapter, chapter_url_source); -- adds bare_url_missing_title error if appropriate
    and stripped of dashes, spaces and other non-isxn-13 characters.
    end


    ]]
    return chapter .. chapter_error;
     
    local function is_valid_isxn_13 (isxn_str)
    local temp=0;
    isxn_str = { isxn_str:byte(1, 13) }; -- make a table of byte values '0' → 0x30 .. '9'  → 0x39
    for i, v in ipairs( isxn_str ) do
    temp = temp + (3 - 2*(i % 2)) * tonumber( string.char(v) ); -- multiply odd index digits by 1, even index digits by 3 and sum; includes check digit
    end
    return temp % 10 == 0; -- sum modulo 10 is zero when isbn-13/ismn is correct
    end
    end


    --[[--------------------------< C H E C K _ I S B N >------------------------------------------------------------
    Determines whether an ISBN string is valid


    --[[
    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 check_isbn( isbn_str )
    local function argument_wrapper( args )
    if nil ~= isbn_str:match("[^%s-0-9X]") then return false; end -- fail if isbn_str contains anything but digits, hyphens, or the uppercase X
    local origin = {};
    isbn_str = isbn_str:gsub( "-", "" ):gsub( " ", "" ); -- remove hyphens and spaces
    local len = isbn_str:len();
    return setmetatable({
    ORIGIN = function( self, k )
    if len ~= 10 and len ~= 13 then
    local dummy = self[k]; --force the variable to be loaded.
    return false;
    return origin[k];
    end
    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] = select_one( args, list, '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'] );
    end
    -- Empty strings, not nil;
    if v == nil then
    v = cfg.defaults[k] or '';
    origin[k] = '';
    end
    tbl = rawset( tbl, k, v );
    return v;
    end,
    });
    end


    if len == 10 then
    --[[
    if isbn_str:match( "^%d*X?$" ) == nil then return false; end
    Looks for a parameter's name in the whitelist.
    return is_valid_isxn(isbn_str, 10);
     
    else
    Parameters in the whitelist can have three values:
    local temp = 0;
    true - active, supported parameters
    if isbn_str:match( "^97[89]%d*$" ) == nil then return false; end -- isbn13 begins with 978 or 979; ismn begins with 979
    false - deprecated, supported parameters
    return is_valid_isxn_13 (isbn_str);
    nil - unsupported parameters
    ]]
     
    local function validate( name )
    local name = tostring( name );
    local state = whitelist.basic_arguments[ name ];
    -- Normal arguments
    if true == state then return true; end -- valid actively supported parameter
    if false == state then
    deprecated_parameter (name); -- parameter is deprecated but still supported
    return true;
    end
    -- Arguments with numbers in them
    name = name:gsub( "%d+", "#" ); -- replace digit(s) with # (last25 becomes last#
    state = whitelist.numbered_arguments[ name ];
    if true == state then return true; end -- valid actively supported parameter
    if false == state then
    deprecated_parameter (name); -- parameter is deprecated but still supported
    return true;
    end
    end
    return false; -- Not supported because not found or name is set to nil
    end
    end


    --[[--------------------------< C H E C K _ I S M N >------------------------------------------------------------


    Determines whether an ISMN string is valid. Similar to isbn-13, ismn is 13 digits begining 979-0-... and uses the
    -- Formats a wiki style internal link
    same check digit calculations. See http://www.ismn-international.org/download/Web_ISMN_Users_Manual_2008-6.pdf
    local function internal_link_id(options)
    section 2, pages 9–12.
    return mw.ustring.format( '[[%s|%s]]%s[[%s%s%s|%s]]',
    options.link, options.label, options.separator or "&nbsp;",
    options.prefix, options.id, options.suffix or "",
    mw.text.nowiki(options.id)
    );
    end


    ]]


    local function ismn (id)
    --[[--------------------------< N O W R A P _ D A T E >--------------------------------------------------------
    local handler = cfg.id_handlers['ISMN'];
     
    local text;
    When date is YYYY-MM-DD format wrap in nowrap span: <span ...>YYYY-MM-DD</span>.  When date is DD MMMM YYYY or is
    local valid_ismn = true;
    MMMM DD, YYYY then wrap in nowrap span: <span ...>DD MMMM</span> YYYY or <span ...>MMMM DD,</span> YYYY


    id=id:gsub( "[%s-–]", "" ); -- strip spaces, hyphens, and endashes from the ismn
    DOES NOT yet support MMMM YYYY or any of the date ranges.


    if 13 ~= id:len() or id:match( "^9790%d*$" ) == nil then -- ismn must be 13 digits and begin 9790
    ]]
    valid_ismn = false;
    else
    valid_ismn=is_valid_isxn_13 (id); -- validate ismn
    end


    -- text = internal_link_id({link = handler.link, label = handler.label, -- use this (or external version) when there is some place to link to
    local function nowrap_date (date)
    -- prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode})
    local cap='';
    local cap2='';
    text="[[" .. handler.link .. "|" .. handler.label .. "]]" .. handler.separator .. id; -- because no place to link to yet


    if false == valid_ismn then
    if date:match("^%d%d%d%d%-%d%d%-%d%d$") then
    text = text .. ' ' .. set_error( 'bad_ismn' ) -- add an error message if the issn is invalid
    date = substitute (cfg.presentation['nowrap1'], date);
    end
    return text;
    elseif date:match("^%a+%s*%d%d?,%s+%d%d%d%d$") or date:match ("^%d%d?%s*%a+%s+%d%d%d%d$") then
    end
    cap, cap2 = string.match (date, "^(.*)%s+(%d%d%d%d)$");
     
    date = substitute (cfg.presentation['nowrap2'], {cap, cap2});
    --[[--------------------------< I S S N >----------------------------------------------------------------------
    end
    return date;
    end


    Validate and format an issn.  This code fixes the case where an editor has included an ISSN in the citation but has separated the two groups of four
    --[[--------------------------< IS _ V A L I D _ I S X N >-----------------------------------------------------
    digits with a space.  When that condition occurred, the resulting link looked like this:


    |issn=0819 4327 gives: [http://www.worldcat.org/issn/0819 4327 0819 4327]  -- can't have spaces in an external link
    ISBN-10 and ISSN validator code calculates checksum across all isbn/issn digits including the check digit. ISBN-13 is checked in check_isbn().
    If the number is valid the result will be 0. Before calling this function, issbn/issn must be checked for length and stripped of dashes,
    This code now prevents that by inserting a hyphen at the issn midpoint. It also validates the issn for length and makes sure that the checkdigit agrees
    spaces and other non-isxn characters.
    with the calculated value.  Incorrect length (8 digits), characters other than 0-9 and X, or checkdigit / calculated value mismatch will all cause a check issn
    error message.  The issn is always displayed with a hyphen, even if the issn was given as a single group of 8 digits.


    ]]
    ]]


    local function issn(id)
    local function is_valid_isxn (isxn_str, len)
    local issn_copy = id; -- save a copy of unadulterated issn; use this version for display if issn does not validate
    local temp = 0;
    local handler = cfg.id_handlers['ISSN'];
    isxn_str = { isxn_str:byte(1, len) }; -- make a table of byte values '0' → 0x30 .. '9'  → 0x39, 'X' → 0x58
    local text;
    len = len+1; -- adjust to be a loop counter
    local valid_issn = true;
    for i, v in ipairs( isxn_str ) do -- loop through all of the bytes and calculate the checksum
    if v == string.byte( "X" ) then -- if checkdigit is X (compares the byte value of 'X' which is 0x58)
    temp = temp + 10*( len - i ); -- it represents 10 decimal
    else
    temp = temp + tonumber( string.char(v) )*(len-i);
    end
    end
    return temp % 11 == 0; -- returns true if calculation result is zero
    end


    id=id:gsub( "[%s-–]", "" ); -- strip spaces, hyphens, and endashes from the issn


    if 8 ~= id:len() or nil == id:match( "^%d*X?$" ) then -- validate the issn: 8 digits long, containing only 0-9 or X in the last position
    --[[--------------------------< IS _ V A L I D _ I S X N  _ 1 3 >----------------------------------------------
    valid_issn=false; -- wrong length or improper character
     
    else
    ISBN-13 and ISMN validator code calculates checksum across all 13 isbn/ismn digits including the check digit.
    valid_issn=is_valid_isxn(id, 8); -- validate issn
    If the number is valid, the result will be 0. Before calling this function, isbn-13/ismn must be checked for length
    end
    and stripped of dashes, spaces and other non-isxn-13 characters.
     
    ]]


    if true == valid_issn then
    local function is_valid_isxn_13 (isxn_str)
    id = string.sub( id, 1, 4 ) .. "-" .. string.sub( id, 5 ); -- if valid, display correctly formatted version
    local temp=0;
    else
    id = issn_copy; -- if not valid, use the show the invalid issn with error message
    isxn_str = { isxn_str:byte(1, 13) }; -- make a table of byte values '0' → 0x30 .. '9'  → 0x39
    for i, v in ipairs( isxn_str ) do
    temp = temp + (3 - 2*(i % 2)) * tonumber( string.char(v) ); -- multiply odd index digits by 1, even index digits by 3 and sum; includes check digit
    end
    end
    return temp % 10 == 0; -- sum modulo 10 is zero when isbn-13/ismn is correct
    text = external_link_id({link = handler.link, label = handler.label,
    prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode})
    if false == valid_issn then
    text = text .. ' ' .. set_error( 'bad_issn' ) -- add an error message if the issn is invalid
    end
    return text
    end
    end


    --[[--------------------------< A M A Z O N >------------------------------------------------------------------
    --[[--------------------------< C H E C K _ I S B N >------------------------------------------------------------


    Formats a link to Amazon.  Do simple error checking: asin must be mix of 10 numeric or uppercase alpha
    Determines whether an ISBN string is valid
    characters.  If a mix, first character must be uppercase alpha; if all numeric, asins must be 10-digit
    isbn. If 10-digit isbn, add a maintenance category so a bot or awb script can replace |asin= with |isbn=.
    Error message if not 10 characters, if not isbn10, if mixed and first character is a digit.


    ]]
    ]]


    local function amazon(id, domain)
    local function check_isbn( isbn_str )
    local err_cat = ""
    if nil ~= isbn_str:match("[^%s-0-9X]") then return false; end -- fail if isbn_str contains anything but digits, hyphens, or the uppercase X
    isbn_str = isbn_str:gsub( "-", "" ):gsub( " ", "" ); -- remove hyphens and spaces
    local len = isbn_str:len();
    if len ~= 10 and len ~= 13 then
    return false;
    end


    if not id:match("^[%d%u][%d%u][%d%u][%d%u][%d%u][%d%u][%d%u][%d%u][%d%u][%d%u]$") then
    if len == 10 then
    err_cat =  ' ' .. set_error ('bad_asin'); -- asin is not a mix of 10 uppercase alpha and numeric characters
    if isbn_str:match( "^%d*X?$" ) == nil then return false; end
    return is_valid_isxn(isbn_str, 10);
    else
    else
    if id:match("^%d%d%d%d%d%d%d%d%d[%dX]$") then -- if 10-digit numeric (or 9 digits with terminal X)
    local temp = 0;
    if check_isbn( id ) then -- see if asin value is isbn10
    if isbn_str:match( "^97[89]%d*$" ) == nil then return false; end -- isbn13 begins with 978 or 979; ismn begins with 979
    add_maint_cat ('ASIN');
    return is_valid_isxn_13 (isbn_str);
    elseif not is_set (err_cat) then
    err_cat = ' ' .. set_error ('bad_asin'); -- asin is not isbn10
    end
    elseif not id:match("^%u[%d%u]+$") then
    err_cat =  ' ' .. set_error ('bad_asin'); -- asin doesn't begin with uppercase alpha
    end
    end
    end
    if not is_set(domain) then
    domain = "com";
    elseif in_array (domain, {'jp', 'uk'}) then -- Japan, United Kingdom
    domain = "co." .. domain;
    elseif in_array (domain, {'au', 'br', 'mx'}) then -- Australia, Brazil, Mexico
    domain = "com." .. domain;
    end
    local handler = cfg.id_handlers['ASIN'];
    return external_link_id({link=handler.link,
    label=handler.label, prefix=handler.prefix .. domain .. "/dp/",
    id=id, encode=handler.encode, separator = handler.separator}) .. err_cat;
    end
    end


    --[[--------------------------< A R X I V >--------------------------------------------------------------------
    --[[--------------------------< C H E C K _ I S M N >------------------------------------------------------------


    See: http://arxiv.org/help/arxiv_identifier
    Determines whether an ISMN string is validSimilar to isbn-13, ismn is 13 digits begining 979-0-... and uses the
     
    same check digit calculations.  See http://www.ismn-international.org/download/Web_ISMN_Users_Manual_2008-6.pdf
    format and error check arXiv identifierThere are three valid forms of the identifier:
    section 2, pages 9–12.
    the first form, valid only between date codes 9108 and 0703 is:
    arXiv:<archive>.<class>/<date code><number><version>
    where:
    <archive> is a string of alpha characters - may be hyphenated; no other punctuation
    <class> is a string of alpha characters - may be hyphenated; no other punctuation
    <date code> is four digits in the form YYMM where YY is the last two digits of the four-digit year and MM is the month number January = 01
    first digit of YY for this form can only 9 and 0
    <number> is a three-digit number
    <version> is a 1 or more digit number preceded with a lowercase v; no spaces (undocumented)
    the second form, valid from April 2007 through December 2014 is:
    arXiv:<date code>.<number><version>
    where:
    <date code> is four digits in the form YYMM where YY is the last two digits of the four-digit year and MM is the month number January = 01
    <number> is a four-digit number
    <version> is a 1 or more digit number preceded with a lowercase v; no spaces


    the third form, valid from January 2015 is:
    arXiv:<date code>.<number><version>
    where:
    <date code> and <version> are as defined for 0704-1412
    <number> is a five-digit number
    ]]
    ]]


    local function arxiv (id, class)
    local function ismn (id)
    local handler = cfg.id_handlers['ARXIV'];
    local handler = cfg.id_handlers['ISMN'];
    local year, month, version;
    local err_cat = '';
    local text;
    local text;
    local valid_ismn = true;
    if id:match("^%a[%a%.%-]+/[90]%d[01]%d%d%d%d$") or id:match("^%a[%a%.%-]+/[90]%d[01]%d%d%d%dv%d+$") then -- test for the 9108-0703 format w/ & w/o version
     
    year, month = id:match("^%a[%a%.%-]+/([90]%d)([01]%d)%d%d%d[v%d]*$");
    id=id:gsub( "[%s-]", "" ); -- strip spaces, hyphens, and endashes from the ismn
    year = tonumber(year);
     
    month = tonumber(month);
    if 13 ~= id:len() or id:match( "^9790%d*$" ) == nil then -- ismn must be 13 digits and begin 9790
    if ((not (90 < year or 8 > year)) or (1 > month or 12 < month)) or -- if invalid year or invalid month
    valid_ismn = false;
    ((91 == year and 7 > month) or (7 == year and 3 < month)) then -- if years ok, are starting and ending months ok?
    err_cat = ' ' .. set_error( 'bad_arxiv' ); -- set error message
    end
    elseif id:match("^%d%d[01]%d%.%d%d%d%d$") or id:match("^%d%d[01]%d%.%d%d%d%dv%d+$") then -- test for the 0704-1412 w/ & w/o version
    year, month = id:match("^(%d%d)([01]%d)%.%d%d%d%d[v%d]*$");
    year = tonumber(year);
    month = tonumber(month);
    if ((7 > year) or (14 < year) or (1 > month or 12 < month)) or -- is year invalid or is month invalid? (doesn't test for future years)
    ((7 == year) and (4 > month)) then --or -- when year is 07, is month invalid (before April)?
    err_cat = ' ' .. set_error( 'bad_arxiv' ); -- set error message
    end
    elseif id:match("^%d%d[01]%d%.%d%d%d%d%d$") or id:match("^%d%d[01]%d%.%d%d%d%d%dv%d+$") then -- test for the 1501- format w/ & w/o version
    year, month = id:match("^(%d%d)([01]%d)%.%d%d%d%d%d[v%d]*$");
    year = tonumber(year);
    month = tonumber(month);
    if ((15 > year) or (1 > month or 12 < month)) then -- is year invalid or is month invalid? (doesn't test for future years)
    err_cat = ' ' .. set_error( 'bad_arxiv' ); -- set error message
    end
    else
    else
    err_cat = ' ' .. set_error( 'bad_arxiv' ); -- arXiv id doesn't match any format
    valid_ismn=is_valid_isxn_13 (id); -- validate ismn
    end
    end


    text = external_link_id({link = handler.link, label = handler.label,
    -- text = internal_link_id({link = handler.link, label = handler.label, -- use this (or external version) when there is some place to link to
    prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode}) .. err_cat;
    -- prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode})
    text="[[" .. handler.link .. "|" .. handler.label .. "]]" .. handler.separator .. id; -- because no place to link to yet


    if is_set (class) then
    if false == valid_ismn then
    class = ' [[' .. '//arxiv.org/archive/' .. class .. ' ' .. class .. ']]'; -- external link within square brackets, not wikilink
    text = text .. ' ' .. set_error( 'bad_ismn' ) -- add an error message if the issn is invalid
    else
    end  
    class = ''; -- empty string for concatenation
    end
    return text .. class;
    return text;
    end
    end


    --[[
    --[[--------------------------< I S S N >----------------------------------------------------------------------
    lccn normalization (http://www.loc.gov/marc/lccn-namespace.html#normalization)
     
    1. Remove all blanks.
    Validate and format an issn. This code fixes the case where an editor has included an ISSN in the citation but has separated the two groups of four
    2. If there is a forward slash (/) in the string, remove it, and remove all characters to the right of the forward slash.
    digits with a space. When that condition occurred, the resulting link looked like this:
    3. If there is a hyphen in the string:
     
    a. Remove it.
    |issn=0819 4327 gives: [http://www.worldcat.org/issn/0819 4327 0819 4327]  -- can't have spaces in an external link
    b. Inspect the substring following (to the right of) the (removed) hyphen. Then (and assuming that steps 1 and 2 have been carried out):
    1. All these characters should be digits, and there should be six or less. (not done in this function)
    This code now prevents that by inserting a hyphen at the issn midpoint. It also validates the issn for length and makes sure that the checkdigit agrees
    2. If the length of the substring is less than 6, left-fill the substring with zeroes until the length is six.
    with the calculated value. Incorrect length (8 digits), characters other than 0-9 and X, or checkdigit / calculated value mismatch will all cause a check issn
    error message. The issn is always displayed with a hyphen, even if the issn was given as a single group of 8 digits.


    Returns a normalized lccn for lccn() to validate.  There is no error checking (step 3.b.1) performed in this function.
    ]]
    ]]


    local function normalize_lccn (lccn)
    local function issn(id)
    lccn = lccn:gsub ("%s", ""); -- 1. strip whitespace
    local issn_copy = id; -- save a copy of unadulterated issn; use this version for display if issn does not validate
    local handler = cfg.id_handlers['ISSN'];
    local text;
    local valid_issn = true;


    if nil ~= string.find (lccn,'/') then
    id=id:gsub( "[%s-–]", "" ); -- strip spaces, hyphens, and endashes from the issn
    lccn = lccn:match ("(.-)/"); -- 2. remove forward slash and all character to the right of it
    end


    local prefix
    if 8 ~= id:len() or nil == id:match( "^%d*X?$" ) then -- validate the issn: 8 digits long, containing only 0-9 or X in the last position
    local suffix
    valid_issn=false; -- wrong length or improper character
    prefix, suffix = lccn:match ("(.+)%-(.+)"); -- 3.a remove hyphen by splitting the string into prefix and suffix
    else
    valid_issn=is_valid_isxn(id, 8); -- validate issn
    end


    if nil ~= suffix then -- if there was a hyphen
    if true == valid_issn then
    suffix=string.rep("0", 6-string.len (suffix)) .. suffix; -- 3.b.2 left fill the suffix with 0s if suffix length less than 6
    id = string.sub( id, 1, 4 ) .. "-" .. string.sub( id, 5 ); -- if valid, display correctly formatted version
    lccn=prefix..suffix; -- reassemble the lccn
    else
    id = issn_copy; -- if not valid, use the show the invalid issn with error message
    end
    end
    return lccn;
    text = external_link_id({link = handler.link, label = handler.label,
    end
    prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode})
    if false == valid_issn then
    text = text .. ' ' .. set_error( 'bad_issn' ) -- add an error message if the issn is invalid
    end
    return text
    end


    --[[
    --[[--------------------------< A M A Z O N >------------------------------------------------------------------
    Format LCCN link and do simple error checking.  LCCN is a character string 8-12 characters long. The length of the LCCN dictates the character type of the first 1-3 characters; the
    rightmost eight are always digits. http://info-uri.info/registry/OAIHandler?verb=GetRecord&metadataPrefix=reg&identifier=info:lccn/


    length = 8 then all digits
    Formats a link to Amazon.  Do simple error checking: asin must be mix of 10 numeric or uppercase alpha
    length = 9 then lccn[1] is lower case alpha
    characters.  If a mix, first character must be uppercase alpha; if all numeric, asins must be 10-digit
    length = 10 then lccn[1] and lccn[2] are both lower case alpha or both digits
    isbn. If 10-digit isbn, add a maintenance category so a bot or awb script can replace |asin= with |isbn=.
    length = 11 then lccn[1] is lower case alpha, lccn[2] and lccn[3] are both lower case alpha or both digits
    Error message if not 10 characters, if not isbn10, if mixed and first character is a digit.
    length = 12 then lccn[1] and lccn[2] are both lower case alpha


    ]]
    ]]


    local function lccn(lccn)
    local function amazon(id, domain)
    local handler = cfg.id_handlers['LCCN'];
    local err_cat = ""
    local err_cat = ''; -- presume that LCCN is valid
    local id = lccn; -- local copy of the lccn


    id = normalize_lccn (id); -- get canonical form (no whitespace, hyphens, forward slashes)
    if not id:match("^[%d%u][%d%u][%d%u][%d%u][%d%u][%d%u][%d%u][%d%u][%d%u][%d%u]$") then
    local len = id:len(); -- get the length of the lccn
    err_cat = ' ' .. set_error ('bad_asin'); -- asin is not a mix of 10 uppercase alpha and numeric characters
     
    else
    if 8 == len then
    if id:match("^%d%d%d%d%d%d%d%d%d[%dX]$") then -- if 10-digit numeric (or 9 digits with terminal X)
    if id:match("[^%d]") then -- if LCCN has anything but digits (nil if only digits)
    if check_isbn( id ) then -- see if asin value is isbn10
    err_cat = ' ' .. set_error( 'bad_lccn' ); -- set an error message
    add_maint_cat ('ASIN');
    end
    elseif not is_set (err_cat) then
    elseif 9 == len then -- LCCN should be adddddddd
    err_cat = ' ' .. set_error ('bad_asin'); -- asin is not isbn10
    if nil == id:match("%l%d%d%d%d%d%d%d%d") then -- does it match our pattern?
    err_cat = ' ' .. set_error( 'bad_lccn' ); -- set an error message
    end
    elseif 10 == len then -- LCCN should be aadddddddd or dddddddddd
    if id:match("[^%d]") then -- if LCCN has anything but digits (nil if only digits) ...
    if nil == id:match("^%l%l%d%d%d%d%d%d%d%d") then -- ... see if it matches our pattern
    err_cat = ' ' .. set_error( 'bad_lccn' ); -- no match, set an error message
    end
    end
    elseif not id:match("^%u[%d%u]+$") then
    err_cat =  ' ' .. set_error ('bad_asin'); -- asin doesn't begin with uppercase alpha
    end
    end
    elseif 11 == len then -- LCCN should be aaadddddddd or adddddddddd
    if not (id:match("^%l%l%l%d%d%d%d%d%d%d%d") or id:match("^%l%d%d%d%d%d%d%d%d%d%d")) then -- see if it matches one of our patterns
    err_cat = ' ' .. set_error( 'bad_lccn' ); -- no match, set an error message
    end
    elseif 12 == len then -- LCCN should be aadddddddddd
    if not id:match("^%l%l%d%d%d%d%d%d%d%d%d%d") then -- see if it matches our pattern
    err_cat = ' ' .. set_error( 'bad_lccn' ); -- no match, set an error message
    end
    else
    err_cat = ' ' .. set_error( 'bad_lccn' ); -- wrong length, set an error message
    end
    end
    if not is_set(domain) then
    domain = "com";
    elseif in_array (domain, {'jp', 'uk'}) then -- Japan, United Kingdom
    domain = "co." .. domain;
    elseif in_array (domain, {'au', 'br', 'mx'}) then -- Australia, Brazil, Mexico
    domain = "com." .. domain;
    end
    local handler = cfg.id_handlers['ASIN'];
    return external_link_id({link=handler.link,
    label=handler.label, prefix=handler.prefix .. domain .. "/dp/",
    id=id, encode=handler.encode, separator = handler.separator}) .. err_cat;
    end


    if not is_set (err_cat) and nil ~= lccn:find ('%s') then
    --[[--------------------------< A R X I V >--------------------------------------------------------------------
    err_cat = ' ' .. set_error( 'bad_lccn' ); -- lccn contains a space, set an error message
    end


    return external_link_id({link = handler.link, label = handler.label,
    See: http://arxiv.org/help/arxiv_identifier
    prefix=handler.prefix,id=lccn,separator=handler.separator, encode=handler.encode}) .. err_cat;
    end


    --[[
    format and error check arXiv identifierThere are three valid forms of the identifier:
    Format PMID and do simple error checkingPMIDs are sequential numbers beginning at 1 and counting up.  This code checks the PMID to see that it
    the first form, valid only between date codes 9108 and 0703 is:
    contains only digits and is less than test_limit; the value in local variable test_limit will need to be updated periodically as more PMIDs are issued.
    arXiv:<archive>.<class>/<date code><number><version>
    ]]
    where:
     
    <archive> is a string of alpha characters - may be hyphenated; no other punctuation
    local function pmid(id)
    <class> is a string of alpha characters - may be hyphenated; no other punctuation
    local test_limit = 30000000; -- update this value as PMIDs approach
    <date code> is four digits in the form YYMM where YY is the last two digits of the four-digit year and MM is the month number January = 01
    local handler = cfg.id_handlers['PMID'];
    first digit of YY for this form can only 9 and 0
    local err_cat =  ''; -- presume that PMID is valid
    <number> is a three-digit number
    <version> is a 1 or more digit number preceded with a lowercase v; no spaces (undocumented)
    if id:match("[^%d]") then -- if PMID has anything but digits
    the second form, valid from April 2007 through December 2014 is:
    err_cat = ' ' .. set_error( 'bad_pmid' ); -- set an error message
    arXiv:<date code>.<number><version>
    else -- PMID is only digits
    where:
    local id_num = tonumber(id); -- convert id to a number for range testing
    <date code> is four digits in the form YYMM where YY is the last two digits of the four-digit year and MM is the month number January = 01
    if 1 > id_num or test_limit < id_num then -- if PMID is outside test limit boundaries
    <number> is a four-digit number
    err_cat = ' ' .. set_error( 'bad_pmid' ); -- set an error message
    <version> is a 1 or more digit number preceded with a lowercase v; no spaces
    end
    end
    return external_link_id({link = handler.link, label = handler.label,
    prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode}) .. err_cat;
    end
     
    --[[--------------------------< I S _ E M B A R G O E D >------------------------------------------------------
     
    Determines if a PMC identifier's online version is embargoed. Compares the date in |embargo= against today's date.  If embargo date is
    in the future, returns the content of |embargo=; otherwise, returns and empty string because the embargo has expired or because
    |embargo= was not set in this cite.


    the third form, valid from January 2015 is:
    arXiv:<date code>.<number><version>
    where:
    <date code> and <version> are as defined for 0704-1412
    <number> is a five-digit number
    ]]
    ]]


    local function is_embargoed (embargo)
    local function arxiv (id, class)
    if is_set (embargo) then
    local handler = cfg.id_handlers['ARXIV'];
    local lang = mw.getContentLanguage();
    local year, month, version;
    local good1, embargo_date, good2, todays_date;
    local err_cat = '';
    good1, embargo_date = pcall( lang.formatDate, lang, 'U', embargo );
    local text;
    good2, todays_date = pcall( lang.formatDate, lang, 'U' );
    if good1 and good2 then -- if embargo date and today's date are good dates
    if id:match("^%a[%a%.%-]+/[90]%d[01]%d%d%d%d$") or id:match("^%a[%a%.%-]+/[90]%d[01]%d%d%d%dv%d+$") then -- test for the 9108-0703 format w/ & w/o version
    if tonumber( embargo_date ) >= tonumber( todays_date ) then -- is embargo date is in the future?
    year, month = id:match("^%a[%a%.%-]+/([90]%d)([01]%d)%d%d%d[v%d]*$");
    return embargo; -- still embargoed
    year = tonumber(year);
    else
    month = tonumber(month);
    add_maint_cat ('embargo')
    if ((not (90 < year or 8 > year)) or (1 > month or 12 < month)) or -- if invalid year or invalid month
    return ''; -- unset because embargo has expired
    ((91 == year and 7 > month) or (7 == year and 3 < month)) then -- if years ok, are starting and ending months ok?
    end
    err_cat = ' ' .. set_error( 'bad_arxiv' ); -- set error message
    end
    elseif id:match("^%d%d[01]%d%.%d%d%d%d$") or id:match("^%d%d[01]%d%.%d%d%d%dv%d+$") then -- test for the 0704-1412 w/ & w/o version
    year, month = id:match("^(%d%d)([01]%d)%.%d%d%d%d[v%d]*$");
    year = tonumber(year);
    month = tonumber(month);
    if ((7 > year) or (14 < year) or (1 > month or 12 < month)) or -- is year invalid or is month invalid? (doesn't test for future years)
    ((7 == year) and (4 > month)) then --or -- when year is 07, is month invalid (before April)?
    err_cat = ' ' .. set_error( 'bad_arxiv' ); -- set error message
    end
    elseif id:match("^%d%d[01]%d%.%d%d%d%d%d$") or id:match("^%d%d[01]%d%.%d%d%d%d%dv%d+$") then -- test for the 1501- format w/ & w/o version
    year, month = id:match("^(%d%d)([01]%d)%.%d%d%d%d%d[v%d]*$");
    year = tonumber(year);
    month = tonumber(month);
    if ((15 > year) or (1 > month or 12 < month)) then -- is year invalid or is month invalid? (doesn't test for future years)
    err_cat = ' ' .. set_error( 'bad_arxiv' ); -- set error message
    end
    end
    else
    err_cat = ' ' .. set_error( 'bad_arxiv' ); -- arXiv id doesn't match any format
    end
    end
    return ''; -- |embargo= not set return empty string
    end


    --[[--------------------------< P M C >------------------------------------------------------------------------
    text = external_link_id({link = handler.link, label = handler.label,
    prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode}) .. err_cat;


    Format a PMC, do simple error checking, and check for embargoed articles.
    if is_set (class) then
    class = ' [[' .. '//arxiv.org/archive/' .. class .. ' ' .. class .. ']]'; -- external link within square brackets, not wikilink
    else
    class = ''; -- empty string for concatenation
    end
    return text .. class;
    end


    The embargo parameter takes a date for a value. If the embargo date is in the future the PMC identifier will not
    --[[
    be linked to the article. If the embargo date is today or in the past, or if it is empty or omitted, then the
    lccn normalization (http://www.loc.gov/marc/lccn-namespace.html#normalization)
    PMC identifier is linked to the article through the link at cfg.id_handlers['PMC'].prefix.
    1. Remove all blanks.
    2. If there is a forward slash (/) in the string, remove it, and remove all characters to the right of the forward slash.
    3. If there is a hyphen in the string:
    a. Remove it.
    b. Inspect the substring following (to the right of) the (removed) hyphen. Then (and assuming that steps 1 and 2 have been carried out):
    1. All these characters should be digits, and there should be six or less. (not done in this function)
    2. If the length of the substring is less than 6, left-fill the substring with zeroes until the length is six.


    PMC embargo date testing is done in function is_embargoed () which is called earlier because when the citation
    Returns a normalized lccn for lccn() to validateThere is no error checking (step 3.b.1) performed in this function.
    has |pmc=<value> but does not have a |url= then |title= is linked with the PMC linkFunction is_embargoed ()
    ]]
    returns the embargo date if the PMC article is still embargoed, otherwise it returns an empty string.


    PMCs are sequential numbers beginning at 1 and counting up.  This code checks the PMC to see that it contains only digits and is less
    local function normalize_lccn (lccn)
    than test_limit; the value in local variable test_limit will need to be updated periodically as more PMCs are issued.
    lccn = lccn:gsub ("%s", ""); -- 1. strip whitespace


    ]]
    if nil ~= string.find (lccn,'/') then
    lccn = lccn:match ("(.-)/"); -- 2. remove forward slash and all character to the right of it
    end


    local function pmc(id, embargo)
    local prefix
    local test_limit = 5000000; -- update this value as PMCs approach
    local suffix
    local handler = cfg.id_handlers['PMC'];
    prefix, suffix = lccn:match ("(.+)%-(.+)"); -- 3.a remove hyphen by splitting the string into prefix and suffix
    local err_cat =  ''; -- presume that PMC is valid
    local text;


    if id:match("[^%d]") then -- if PMC has anything but digits
    if nil ~= suffix then -- if there was a hyphen
    err_cat = ' ' .. set_error( 'bad_pmc' ); -- set an error message
    suffix=string.rep("0", 6-string.len (suffix)) .. suffix; -- 3.b.2 left fill the suffix with 0s if suffix length less than 6
    else -- PMC is only digits
    lccn=prefix..suffix; -- reassemble the lccn
    local id_num = tonumber(id); -- convert id to a number for range testing
    if 1 > id_num or test_limit < id_num then -- if PMC is outside test limit boundaries
    err_cat = ' ' .. set_error( 'bad_pmc' ); -- set an error message
    end
    end
    end
    if is_set (embargo) then -- is PMC is still embargoed?
    return lccn;
    text="[[" .. handler.link .. "|" .. handler.label .. "]]:" .. handler.separator .. id .. err_cat; -- still embargoed so no external link
    else
    text = external_link_id({link = handler.link, label = handler.label, -- no embargo date or embargo has expired, ok to link to article
    prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode}) .. err_cat;
    end
    end
    return text;
    end


    -- Formats a DOI and checks for DOI errors.
    --[[
    Format LCCN link and do simple error checking.  LCCN is a character string 8-12 characters long. The length of the LCCN dictates the character type of the first 1-3 characters; the
    rightmost eight are always digits. http://info-uri.info/registry/OAIHandler?verb=GetRecord&metadataPrefix=reg&identifier=info:lccn/


    -- DOI names contain two parts: prefix and suffix separated by a forward slash.
    length = 8 then all digits
    --  Prefix: directory indicator '10.' followed by a registrant code
    length = 9 then lccn[1] is lower case alpha
    --  Suffix: character string of any length chosen by the registrant
    length = 10 then lccn[1] and lccn[2] are both lower case alpha or both digits
    length = 11 then lccn[1] is lower case alpha, lccn[2] and lccn[3] are both lower case alpha or both digits
    length = 12 then lccn[1] and lccn[2] are both lower case alpha


    -- This function checks a DOI name for: prefix/suffixIf the doi name contains spaces or endashes,
    ]]
    -- or, if it ends with a period or a comma, this function will emit a bad_doi error message.
     
    local function lccn(lccn)
    local handler = cfg.id_handlers['LCCN'];
    local err_cat = ''; -- presume that LCCN is valid
    local id = lccn; -- local copy of the lccn


    -- DOI names are case-insensitive and can incorporate any printable Unicode characters so the test for spaces, endash,
    id = normalize_lccn (id); -- get canonical form (no whitespace, hyphens, forward slashes)
    -- and terminal punctuation may not be technically correct but it appears, that in practice these characters are rarely if ever used in doi names.
    local len = id:len(); -- get the length of the lccn


    local function doi(id, inactive)
    if 8 == len then
    local cat = ""
    if id:match("[^%d]") then -- if LCCN has anything but digits (nil if only digits)
    local handler = cfg.id_handlers['DOI'];
    err_cat = ' ' .. set_error( 'bad_lccn' ); -- set an error message
    local text;
    if is_set(inactive) then
    local inactive_year = inactive:match("%d%d%d%d") or ''; -- try to get the year portion from the inactive date
    text = "[[" .. handler.link .. "|" .. handler.label .. "]]:" .. id;
    if is_set(inactive_year) then
    table.insert( z.error_categories, "Pages with DOIs inactive since " .. inactive_year );
    else
    table.insert( z.error_categories, "Pages with inactive DOIs" ); -- when inactive doesn't contain a recognizable year
    end
    end
    inactive = " (" .. cfg.messages['inactive'] .. " " .. inactive .. ")"
    elseif 9 == len then -- LCCN should be adddddddd
    else
    if nil == id:match("%l%d%d%d%d%d%d%d%d") then -- does it match our pattern?
    text = external_link_id({link = handler.link, label = handler.label,
    err_cat = ' ' .. set_error( 'bad_lccn' ); -- set an error message
    prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode})
    end
    inactive = ""
    elseif 10 == len then -- LCCN should be aadddddddd or dddddddddd
    end
    if id:match("[^%d]") then -- if LCCN has anything but digits (nil if only digits) ...
    if nil == id:match("^%l%l%d%d%d%d%d%d%d%d") then -- ... see if it matches our pattern
    err_cat = ' ' .. set_error( 'bad_lccn' ); -- no match, set an error message
    end
    end
    elseif 11 == len then -- LCCN should be aaadddddddd or adddddddddd
    if not (id:match("^%l%l%l%d%d%d%d%d%d%d%d") or id:match("^%l%d%d%d%d%d%d%d%d%d%d")) then -- see if it matches one of our patterns
    err_cat = ' ' .. set_error( 'bad_lccn' ); -- no match, set an error message
    end
    elseif 12 == len then -- LCCN should be aadddddddddd
    if not id:match("^%l%l%d%d%d%d%d%d%d%d%d%d") then -- see if it matches our pattern
    err_cat = ' ' .. set_error( 'bad_lccn' ); -- no match, set an error message
    end
    else
    err_cat = ' ' .. set_error( 'bad_lccn' ); -- wrong length, set an error message
    end


    if nil == id:match("^10%.[^%s–]-/[^%s–]-[^%.,]$") then -- doi must begin with '10.', must contain a fwd slash, must not contain spaces or endashes, and must not end with period or comma
    if not is_set (err_cat) and nil ~= lccn:find ('%s') then
    cat = ' ' .. set_error( 'bad_doi' );
    err_cat = ' ' .. set_error( 'bad_lccn' ); -- lccn contains a space, set an error message
    end
    end
    return text .. inactive .. cat
     
    return external_link_id({link = handler.link, label = handler.label,
    prefix=handler.prefix,id=lccn,separator=handler.separator, encode=handler.encode}) .. err_cat;
    end
    end


    -- Formats an OpenLibrary link, and checks for associated errors.
    --[[
    local function openlibrary(id)
    Format PMID and do simple error checking.  PMIDs are sequential numbers beginning at 1 and counting up.  This code checks the PMID to see that it
    local code = id:match("^%d+([AMW])$"); -- only digits followed by 'A', 'M', or 'W'
    contains only digits and is less than test_limit; the value in local variable test_limit will need to be updated periodically as more PMIDs are issued.
    local handler = cfg.id_handlers['OL'];
    ]]


    if ( code == "A" ) then
    local function pmid(id)
    return external_link_id({link=handler.link, label=handler.label,
    local test_limit = 30000000; -- update this value as PMIDs approach
    prefix=handler.prefix .. 'authors/OL',
    local handler = cfg.id_handlers['PMID'];
    id=id, separator=handler.separator, encode = handler.encode})
    local err_cat = ''; -- presume that PMID is valid
    elseif ( code == "M" ) then
    return external_link_id({link=handler.link, label=handler.label,
    if id:match("[^%d]") then -- if PMID has anything but digits
    prefix=handler.prefix .. 'books/OL',
    err_cat = ' ' .. set_error( 'bad_pmid' ); -- set an error message
    id=id, separator=handler.separator, encode = handler.encode})
    else -- PMID is only digits
    elseif ( code == "W" ) then
    local id_num = tonumber(id); -- convert id to a number for range testing
    return external_link_id({link=handler.link, label=handler.label,
    if 1 > id_num or test_limit < id_num then -- if PMID is outside test limit boundaries
    prefix=handler.prefix .. 'works/OL',
    err_cat = ' ' .. set_error( 'bad_pmid' ); -- set an error message
    id=id, separator=handler.separator, encode = handler.encode})
    end
    else
    return external_link_id({link=handler.link, label=handler.label,
    prefix=handler.prefix .. 'OL',
    id=id, separator=handler.separator, encode = handler.encode}) .. ' ' .. set_error( 'bad_ol' );
    end
    end
    return external_link_id({link = handler.link, label = handler.label,
    prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode}) .. err_cat;
    end
    end


    --[[--------------------------< I S _ E M B A R G O E D >------------------------------------------------------


    --[[--------------------------< M E S S A G E _ I D >----------------------------------------------------------
    Determines if a PMC identifier's online version is embargoed. Compares the date in |embargo= against today's dateIf embargo date is
     
    in the future, returns the content of |embargo=; otherwise, returns and empty string because the embargo has expired or because
    Validate and format a usenet message idSimple error checking, looks for 'id-left@id-right' not enclosed in
    |embargo= was not set in this cite.
    '<' and/or '>' angle brackets.


    ]]
    ]]


    local function message_id (id)
    local function is_embargoed (embargo)
    local handler = cfg.id_handlers['USENETID'];
    if is_set (embargo) then
     
    local lang = mw.getContentLanguage();
    text = external_link_id({link = handler.link, label = handler.label,
    local good1, embargo_date, good2, todays_date;
    prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode})
    good1, embargo_date = pcall( lang.formatDate, lang, 'U', embargo );
    good2, todays_date = pcall( lang.formatDate, lang, 'U' );
    if not id:match('^.+@.+$') or not id:match('^[^<].*[^>]$')then -- doesn't have '@' or has one or first or last character is '< or '>'
    text = text .. ' ' .. set_error( 'bad_message_id' ) -- add an error message if the message id is invalid
    end
    return text
    if good1 and good2 then -- if embargo date and today's date are good dates
    if tonumber( embargo_date ) >= tonumber( todays_date ) then -- is embargo date is in the future?
    return embargo; -- still embargoed
    else
    add_maint_cat ('embargo')
    return ''; -- unset because embargo has expired
    end
    end
    end
    return ''; -- |embargo= not set return empty string
    end
    end


    --[[--------------------------< S E T _ T I T L E T Y P E >----------------------------------------------------
    --[[--------------------------< P M C >------------------------------------------------------------------------
     
    Format a PMC, do simple error checking, and check for embargoed articles.
     
    The embargo parameter takes a date for a value. If the embargo date is in the future the PMC identifier will not
    be linked to the article.  If the embargo date is today or in the past, or if it is empty or omitted, then the
    PMC identifier is linked to the article through the link at cfg.id_handlers['PMC'].prefix.
     
    PMC embargo date testing is done in function is_embargoed () which is called earlier because when the citation
    has |pmc=<value> but does not have a |url= then |title= is linked with the PMC link.  Function is_embargoed ()
    returns the embargo date if the PMC article is still embargoed, otherwise it returns an empty string.


    This function sets default title types (equivalent to the citation including |type=<default value>) for those templates that have defaults.
    PMCs are sequential numbers beginning at 1 and counting up.  This code checks the PMC to see that it contains only digits and is less
    Also handles the special case where it is desirable to omit the title type from the rendered citation (|type=none).
    than test_limit; the value in local variable test_limit will need to be updated periodically as more PMCs are issued.


    ]]
    ]]


    local function set_titletype (cite_class, title_type)
    local function pmc(id, embargo)
    if is_set(title_type) then
    local test_limit = 5000000; -- update this value as PMCs approach
    if "none" == title_type then
    local handler = cfg.id_handlers['PMC'];
    title_type = ""; -- if |type=none then type parameter not displayed
    local err_cat =  ''; -- presume that PMC is valid
    local text;
     
    if id:match("[^%d]") then -- if PMC has anything but digits
    err_cat = ' ' .. set_error( 'bad_pmc' ); -- set an error message
    else -- PMC is only digits
    local id_num = tonumber(id); -- convert id to a number for range testing
    if 1 > id_num or test_limit < id_num then -- if PMC is outside test limit boundaries
    err_cat = ' ' .. set_error( 'bad_pmc' ); -- set an error message
    end
    end
    return title_type; -- if |type= has been set to any other value use that value
    end
    end
     
    return cfg.title_types [cite_class] or ''; -- set template's default title type; else empty string for concatenation
    if is_set (embargo) then -- is PMC is still embargoed?
    text="[[" .. handler.link .. "|" .. handler.label .. "]]:" .. handler.separator .. id .. err_cat; -- still embargoed so no external link
    else
    text = external_link_id({link = handler.link, label = handler.label, -- no embargo date or embargo has expired, ok to link to article
    prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode}) .. err_cat;
    end
    return text;
    end
    end


    --[[--------------------------< C L E A N _ I S B N >----------------------------------------------------------
    -- Formats a DOI and checks for DOI errors.


    Removes irrelevant text and dashes from ISBN number
    -- DOI names contain two parts: prefix and suffix separated by a forward slash.
    Similar to that used for Special:BookSources
    --  Prefix: directory indicator '10.' followed by a registrant code
    --  Suffix: character string of any length chosen by the registrant


    ]]
    -- This function checks a DOI name for: prefix/suffix.  If the doi name contains spaces or endashes,
    -- or, if it ends with a period or a comma, this function will emit a bad_doi error message.


    local function clean_isbn( isbn_str )
    -- DOI names are case-insensitive and can incorporate any printable Unicode characters so the test for spaces, endash,
    return isbn_str:gsub( "[^-0-9X]", "" );
    -- and terminal punctuation may not be technically correct but it appears, that in practice these characters are rarely if ever used in doi names.
    end


    --[[--------------------------< E S C A P E _ L U A _ M A G I C _ C H A R S >----------------------------------
    local function doi(id, inactive)
    local cat = ""
    local handler = cfg.id_handlers['DOI'];
    local text;
    if is_set(inactive) then
    local inactive_year = inactive:match("%d%d%d%d") or ''; -- try to get the year portion from the inactive date
    text = "[[" .. handler.link .. "|" .. handler.label .. "]]:" .. id;
    if is_set(inactive_year) then
    table.insert( z.error_categories, "Pages with DOIs inactive since " .. inactive_year );
    else
    table.insert( z.error_categories, "Pages with inactive DOIs" ); -- when inactive doesn't contain a recognizable year
    end
    inactive = " (" .. cfg.messages['inactive'] .. " " .. inactive .. ")"
    else
    text = external_link_id({link = handler.link, label = handler.label,
    prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode})
    inactive = ""
    end


    Returns a string where all of lua's magic characters have been escaped.  This is important because functions like
    if nil == id:match("^10%.[^%s–]-/[^%s–]-[^%.,]$") then -- doi must begin with '10.', must contain a fwd slash, must not contain spaces or endashes, and must not end with period or comma
    string.gsub() treat their pattern and replace strings as patterns, not literal strings.
    cat = ' ' .. set_error( 'bad_doi' );
    ]]
    end
    local function escape_lua_magic_chars (argument)
    return text .. inactive .. cat
    argument = argument:gsub("%%", "%%%%"); -- replace % with %%
    argument = argument:gsub("([%^%$%(%)%.%[%]%*%+%-%?])", "%%%1"); -- replace all other lua magic pattern characters
    return argument;
    end
    end


    --[[--------------------------< S T R I P _ A P O S T R O P H E _ M A R K U P >--------------------------------


    Strip wiki italic and bold markup from argument so that it doesn't contaminate COinS metadata.
    --[[--------------------------< O P E N L I B R A R Y >--------------------------------------------------------
    This function strips common patterns of apostrophe markup.  We presume that editors who have taken the time to
     
    markup a title have, as a result, provided valid markup. When they don't, some single apostrophes are left behind.
    Formats an OpenLibrary link, and checks for associated errors.


    ]]
    ]]
    local function openlibrary(id)
    local code = id:match("^%d+([AMW])$"); -- only digits followed by 'A', 'M', or 'W'
    local handler = cfg.id_handlers['OL'];


    local function strip_apostrophe_markup (argument)
    if ( code == "A" ) then
    if not is_set (argument) then return argument; end
    return external_link_id({link=handler.link, label=handler.label,
     
    prefix=handler.prefix .. 'authors/OL',
    while true do
    id=id, separator=handler.separator, encode = handler.encode})
    if argument:match ("%'%'%'%'%'") then -- bold italic (5)
    elseif ( code == "M" ) then
    argument=argument:gsub("%'%'%'%'%'", ""); -- remove all instances of it
    return external_link_id({link=handler.link, label=handler.label,
    elseif argument:match ("%'%'%'%'") then -- italic start and end without content (4)
    prefix=handler.prefix .. 'books/OL',
    argument=argument:gsub("%'%'%'%'", "");
    id=id, separator=handler.separator, encode = handler.encode})
    elseif argument:match ("%'%'%'") then -- bold (3)
    elseif ( code == "W" ) then
    argument=argument:gsub("%'%'%'", "");
    return external_link_id({link=handler.link, label=handler.label,
    elseif argument:match ("%'%'") then -- italic (2)
    prefix=handler.prefix .. 'works/OL',
    argument=argument:gsub("%'%'", "");
    id=id, separator=handler.separator, encode = handler.encode})
    else
    else
    break;
    return external_link_id({link=handler.link, label=handler.label,
    end
    prefix=handler.prefix .. 'OL',
    id=id, separator=handler.separator, encode = handler.encode}) .. ' ' .. set_error( 'bad_ol' );
    end
    end
    return argument; -- done
    end
    end


    --[[--------------------------< M A K E _ C O I N S _ T I T L E >----------------------------------------------


    Makes a title for COinS from Title and / or ScriptTitle (or any other name-script pairs)
    --[[--------------------------< M E S S A G E _ I D >----------------------------------------------------------
     
    Validate and format a usenet message id.  Simple error checking, looks for 'id-left@id-right' not enclosed in
    '<' and/or '>' angle brackets.


    Apostrophe markup (bold, italics) is stripped from each value so that the COinS metadata isn't correupted with strings
    of %27%27...
    ]]
    ]]


    local function make_coins_title (title, script)
    local function message_id (id)
    if is_set (title) then
    local handler = cfg.id_handlers['USENETID'];
    title = strip_apostrophe_markup (title); -- strip any apostrophe markup
     
    else
    text = external_link_id({link = handler.link, label = handler.label,
    title=''; -- if not set, make sure title is an empty string
    prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode})
    end
    if is_set (script) then
    if not id:match('^.+@.+$') or not id:match('^[^<].*[^>]$')then -- doesn't have '@' or has one or first or last character is '< or '>'
    script = script:gsub ('^%l%l%s*:%s*', ''); -- remove language prefix if present (script value may now be empty string)
    text = text .. ' ' .. set_error( 'bad_message_id' ) -- add an error message if the message id is invalid
    script = strip_apostrophe_markup (script); -- strip any apostrophe markup
    end  
    else
    script=''; -- if not set, make sure script is an empty string
    return text
    end
    if is_set (title) and is_set (script) then
    script = ' ' .. script; -- add a space before we concatenate
    end
    return title .. script; -- return the concatenation
    end
    end


    --[[--------------------------< G E T _ C O I N S _ P A G E S >------------------------------------------------
    --[[--------------------------< S E T _ T I T L E T Y P E >----------------------------------------------------


    Extract page numbers from external wikilinks in any of the |page=, |pages=, or |at= parameters for use in COinS.
    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 get_coins_pages (pages)
    local function set_titletype (cite_class, title_type)
    local pattern;
    if is_set(title_type) then
    if not is_set (pages) then return pages; end -- if no page numbers then we're done
    if "none" == title_type then
    title_type = ""; -- if |type=none then type parameter not displayed
    while true do
    end
    pattern = pages:match("%[(%w*:?//[^ ]+%s+)[%w%d].*%]"); -- pattern is the opening bracket, the url and following space(s): "[url "
    return title_type; -- if |type= has been set to any other value use that value
    if nil == pattern then break; end -- no more urls
    pattern = escape_lua_magic_chars (pattern); -- pattern is not a literal string; escape lua's magic pattern characters
    pages = pages:gsub(pattern, ""); -- remove as many instances of pattern as possible
    end
    end
    pages = pages:gsub("[%[%]]", ""); -- remove the brackets
    pages = pages:gsub("–", "-" ); -- replace endashes with hyphens
    pages = pages:gsub("&%w+;", "-" ); -- and replace html entities (&ndash; etc.) with hyphens; do we need to replace numerical entities like &#32; and the like?
    return pages;
    end


    -- Gets the display text for a wikilink like [[A|B]] or [[B]] gives B
    return cfg.title_types [cite_class] or ''; -- set template's default title type; else empty string for concatenation
    local function remove_wiki_link( str )
    return (str:gsub( "%[%[([^%[%]]*)%]%]", function(l)
    return l:gsub( "^[^|]*|(.*)$", "%1" ):gsub("^%s*(.-)%s*$", "%1");
    end));
    end
    end


    -- Converts a hyphen to a dash
    --[[--------------------------< C L E A N _ I S B N >----------------------------------------------------------
    local function hyphen_to_dash( str )
    if not is_set(str) or str:match( "[%[%]{}<>]" ) ~= nil then
    return str;
    end
    return str:gsub( '-', '–' );
    end


    --[[--------------------------< S A F E _ J O I N >------------------------------------------------------------
    Removes irrelevant text and dashes from ISBN number
    Similar to that used for Special:BookSources


    Joins a sequence of strings together while checking for duplicate separation characters.
    ]]
     
    local function clean_isbn( isbn_str )
    return isbn_str:gsub( "[^-0-9X]", "" );
    end
     
    --[[--------------------------< E S C A P E _ L U A _ M A G I C _ C H A R S >----------------------------------
     
    Returns a string where all of lua's magic characters have been escaped.  This is important because functions like
    string.gsub() treat their pattern and replace strings as patterns, not literal strings.
    ]]
    local function escape_lua_magic_chars (argument)
    argument = argument:gsub("%%", "%%%%"); -- replace % with %%
    argument = argument:gsub("([%^%$%(%)%.%[%]%*%+%-%?])", "%%%1"); -- replace all other lua magic pattern characters
    return argument;
    end
     
    --[[--------------------------< S T R I P _ A P O S T R O P H E _ M A R K U P >--------------------------------
     
    Strip wiki italic and bold markup from argument so that it doesn't contaminate COinS metadata.
    This function strips common patterns of apostrophe markup.  We presume that editors who have taken the time to
    markup a title have, as a result, provided valid markup. When they don't, some single apostrophes are left behind.


    ]]
    ]]


    local function safe_join( tbl, duplicate_char )
    local function strip_apostrophe_markup (argument)
    --[[
    if not is_set (argument) then return argument; end
    Note: we use string functions here, rather than ustring functions.
     
    while true do
    This has considerably faster performance and should work correctly as
    if argument:match ("%'%'%'%'%'") then -- bold italic (5)
    long as the duplicate_char is strict ASCII.  The strings
    argument=argument:gsub("%'%'%'%'%'", ""); -- remove all instances of it
    in tbl may be ASCII or UTF8.
    elseif argument:match ("%'%'%'%'") then -- italic start and end without content (4)
    ]]
    argument=argument:gsub("%'%'%'%'", "");
    elseif argument:match ("%'%'%'") then -- bold (3)
    local str = ''; -- the output string
    argument=argument:gsub("%'%'%'", "");
    local comp = ''; -- what does 'comp' mean?
    elseif argument:match ("%'%'") then -- italic (2)
    local end_chr = '';
    argument=argument:gsub("%'%'", "");
    local trim;
    else
    for _, value in ipairs( tbl ) do
    break;
    if value == nil then value = ''; end
    end
    end
    if str == '' then -- if output string is empty
    return argument; -- done
    str = value; -- assign value to it (first time through the loop)
    end
    elseif value ~= '' then
     
    if value:sub(1,1) == '<' then -- Special case of values enclosed in spans and other markup.
    --[[--------------------------< M A K E _ C O I N S _ T I T L E >----------------------------------------------
    comp = value:gsub( "%b<>", "" ); -- remove html markup (<span>string</span> -> string)
     
    else
    Makes a title for COinS from Title and / or ScriptTitle (or any other name-script pairs)
    comp = value;
     
    end
    Apostrophe markup (bold, italics) is stripped from each value so that the COinS metadata isn't correupted with strings
    -- typically duplicate_char is sepc
    of %27%27...
    if comp:sub(1,1) == duplicate_char then -- is first charactier same as duplicate_char? why test first character?
    ]]
    --   Because individual string segments often (always?) begin with terminal punct for th
    --   preceding segment: 'First element' .. 'sepc next element' .. etc?
    trim = false;
    end_chr = str:sub(-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 = str:sub(1,-2); -- remove it
    elseif end_chr == "'" then -- if it might be wikimarkup
    if str:sub(-3,-1) == duplicate_char .. "''" then -- if last three chars of str are sepc''
    str = str:sub(1, -4) .. "''"; -- remove them and add back ''
    elseif str:sub(-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 str:sub(-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 wikimarkup
    if str:sub(-3,-1) == duplicate_char .. "]]" then -- if last three chars of str are sepc]] wikilink
    trim = true;
    elseif str:sub(-2,-1) == duplicate_char .. "]" then -- if last two chars of str are sepc] external link
    trim = true;
    elseif str:sub(-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 str:sub(-2,-1) == duplicate_char .. " " then -- if last two chars of str are <sepc><space>
    str = str:sub(1,-3); -- remove them both
    end
    end


    if trim then
    local function make_coins_title (title, script)
    if value ~= comp then -- value does not equal comp when value contains html markup
    if is_set (title) then
    local dup2 = duplicate_char;
    title = strip_apostrophe_markup (title); -- strip any apostrophe markup
    if dup2:match( "%A" ) then dup2 = "%" .. dup2; end -- if duplicate_char not a letter then escape it
    else
    title=''; -- if not set, make sure title is an empty string
    value = value:gsub( "(%b<>)" .. dup2, "%1", 1 ) -- remove duplicate_char if it follows html markup
    end
    else
    if is_set (script) then
    value = value:sub( 2, -1 ); -- remove duplicate_char when it is first character
    script = script:gsub ('^%l%l%s*:%s*', ''); -- remove language prefix if present (script value may now be empty string)
    end
    script = strip_apostrophe_markup (script); -- strip any apostrophe markup
    end
    else
    end
    script=''; -- if not set, make sure script is an empty string
    str = str .. value; --add it to the output string
    end
    end
    if is_set (title) and is_set (script) then
    script = ' ' .. script; -- add a space before we concatenate
    end
    end
    return str;
    return title .. script; -- return the concatenation
    end
    end


    --[[--------------------------< I S _ G O O D _ V A N C _ N A M E >--------------------------------------------
    --[[--------------------------< G E T _ C O I N S _ P A G E S >------------------------------------------------


    For Vancouver Style, author/editor names are supposed to be rendered in Latin (read ASCII) characters.  When a name
    Extract page numbers from external wikilinks in any of the |page=, |pages=, or |at= parameters for use in COinS.
    uses characters that contain diacritical marks, those characters are to 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.
    These things are not currently possible in this module so are left to the editor to do.
     
    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
     
    At the time of this writing, I had to write the 'if nil == mw.ustring.find ...' test ouside of the code editor and paste it here
    because the code editor gets confused between character insertion point and cursor position.


    ]]
    ]]


    local function is_good_vanc_name (last, first)
    local function get_coins_pages (pages)
    if nil == mw.ustring.find (last, "^[A-Za-zÀ-ÖØ-öø-ƿDŽ-ɏ%-%s%']*$") or nil == mw.ustring.find (first, "^[A-Za--ÖØ-öø-ƿDŽ-ɏ%-%s%'%.]*$") then
    local pattern;
    add_vanc_error ();
    if not is_set (pages) then return pages; end -- if no page numbers then we're done
    return false; -- not a string of latin characters; Vancouver required Romanization
    end;
    while true do
    return true;
    pattern = pages:match("%[(%w*:?//[^ ]+%s+)[%w%d].*%]"); -- pattern is the opening bracket, the url and following space(s): "[url "
    if nil == pattern then break; end -- no more urls
    pattern = escape_lua_magic_chars (pattern); -- pattern is not a literal string; escape lua's magic pattern characters
    pages = pages:gsub(pattern, ""); -- remove as many instances of pattern as possible
    end
    pages = pages:gsub("[%[%]]", ""); -- remove the brackets
    pages = pages:gsub("–", "-" ); -- replace endashes with hyphens
    pages = pages:gsub("&%w+;", "-" ); -- and replace html entities (&ndash; etc.) with hyphens; do we need to replace numerical entities like &#32; and the like?
    return pages;
    end
    end


    --[[--------------------------< R E D U C E _ T O _ I N I T I A L S >------------------------------------------
    -- Gets the display text for a wikilink like [[A|B]] or [[B]] gives B
    local function remove_wiki_link( str )
    return (str:gsub( "%[%[([^%[%]]*)%]%]", function(l)
    return l:gsub( "^[^|]*|(.*)$", "%1" ):gsub("^%s*(.-)%s*$", "%1");
    end));
    end


    Attempts to convert names to initials in support of |name-list-format=vanc. 
    -- Converts a hyphen to a dash
    local function hyphen_to_dash( str )
    if not is_set(str) or str:match( "[%[%]{}<>]" ) ~= nil then
    return str;
    end
    return str:gsub( '-', '–' );
    end


    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/.
    --[[--------------------------< S A F E _ J O I N >------------------------------------------------------------


    Vancouver style requires family rank designations (Jr, II, III, etc) to be rendered as Jr, 2nd, 3rd, etc.  This form is not
    Joins a sequence of strings together while checking for duplicate separation characters.
    currently supported by this code so correctly formed names like Smith JL 2nd are converted to Smith J2. See http://www.ncbi.nlm.nih.gov/books/NBK7271/box/A35085/.
     
    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)
    local function safe_join( tbl, duplicate_char )
    if mw.ustring.match(first, "^%u%u$") then return first end; -- when first contains just two upper-case letters, nothing to do
    --[[
    local initials = {}
    Note: we use string functions here, rather than ustring functions.
    local i = 0; -- counter for number of initials
    for word in mw.ustring.gmatch(first, "[^%s%.%-]+") do -- names separated by spaces, hyphens, or periods
    This has considerably faster performance and should work correctly as
    table.insert(initials, mw.ustring.sub(word,1,1)) -- Vancouver format does not include full stops.
    long as the duplicate_char is strict ASCII. The strings
    i = i + 1; -- bump the counter
    in tbl may be ASCII or UTF8.
    if 2 <= i then break; end -- only two initials allowed in Vancouver system; if 2, quit
    ]]
    end
    return table.concat(initials) -- Vancouver format does not include spaces.
    local str = ''; -- the output string
    end
    local comp = ''; -- what does 'comp' mean?
     
    local end_chr = '';
    --[[--------------------------< L I S T  _ P E O P L E >-------------------------------------------------------
    local trim;
     
    for _, value in ipairs( tbl ) do
    Formats a list of people (e.g. authors / editors)
    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 comp:sub(1,1) == duplicate_char then -- is first charactier same as duplicate_char? why test first character?
    --  Because individual string segments often (always?) begin with terminal punct for th
    --   preceding segment: 'First element' .. 'sepc next element' .. etc?
    trim = false;
    end_chr = str:sub(-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 = str:sub(1,-2); -- remove it
    elseif end_chr == "'" then -- if it might be wikimarkup
    if str:sub(-3,-1) == duplicate_char .. "''" then -- if last three chars of str are sepc''
    str = str:sub(1, -4) .. "''"; -- remove them and add back ''
    elseif str:sub(-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 str:sub(-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 wikimarkup
    if str:sub(-3,-1) == duplicate_char .. "]]" then -- if last three chars of str are sepc]] wikilink
    trim = true;
    elseif str:sub(-2,-1) == duplicate_char .. "]" then -- if last two chars of str are sepc] external link
    trim = true;
    elseif str:sub(-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 str:sub(-2,-1) == duplicate_char .. " " then -- if last two chars of str are <sepc><space>
    str = str:sub(1,-3); -- remove them both
    end
    end


    local function list_people(control, people, etal)
    if trim then
    local sep;
    if value ~= comp then -- value does not equal comp when value contains html markup
    local namesep;
    local dup2 = duplicate_char;
    local format = control.format
    if dup2:match( "%A" ) then dup2 = "%" .. dup2; end -- if duplicate_char not a letter then escape it
    local maximum = control.maximum
    local lastauthoramp = control.lastauthoramp;
    value = value:gsub( "(%b<>)" .. dup2, "%1", 1 ) -- remove duplicate_char if it follows html markup
    local text = {}
    else
    value = value:sub( 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 _ 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 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.
    These things are not currently possible in this module so are left to the editor to do.


    if 'vanc' == format then -- Vancouver-like author/editor name styling?
    This test allows |first= and |last= names to contain any of the letters defined in the four Unicode Latin character sets
    sep = ','; -- name-list separator between authors is a comma
    [http://www.unicode.org/charts/PDF/U0000.pdf C0 Controls and Basic Latin] 0041–005A, 0061–007A
    namesep = ' '; -- last/first separator is a space
    [http://www.unicode.org/charts/PDF/U0080.pdf C1 Controls and Latin-1 Supplement] 00C0–00D6, 00D8–00F6, 00F8–00FF
    else
    [http://www.unicode.org/charts/PDF/U0100.pdf Latin Extended-A] 0100–017F
    sep = ';' -- name-list separator between authors is a semicolon
    [http://www.unicode.org/charts/PDF/U0180.pdf Latin Extended-B] 0180–01BF, 01C4–024F
    namesep = ', ' -- last/first separator is <comma><space>
    end
    if sep:sub(-1,-1) ~= " " then sep = sep .. " " end
    if is_set (maximum) and maximum < 1 then return "", 0; end -- returned 0 is for EditorCount; not used for authors
    for i,person in ipairs(people) do
    if is_set(person.last) then
    local mask = person.mask
    local one
    local sep_one = sep;
    if is_set (maximum) and i > maximum then
    etal = true;
    break;
    elseif (mask ~= nil) then
    local n = tonumber(mask)
    if (n ~= nil) then
    one = string.rep("&mdash;",n)
    else
    one = mask;
    sep_one = " ";
    end
    else
    one = person.last
    local first = person.first
    if 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) then -- and name is all Latin characters; corporate authors not tested
    first = reduce_to_initials(first) -- attempt to convert first name(s) to initials
    end
    end
    one = one .. namesep .. first
    end
    if is_set(person.link) and person.link ~= control.page_name then
    one = "[[" .. person.link .. "|" .. one .. "]]" -- link author/editor if this page is not the author's/editor's page
    end


    if is_set(person.link) and ((nil ~= person.link:find("//")) or (nil ~= person.link:find("[%[%]]"))) then
    |lastn= also allowed to contain hyphens, spaces, and apostrophes. (http://www.ncbi.nlm.nih.gov/books/NBK7271/box/A35029/)
    one = one .. " " .. set_error( 'bad_authorlink' ) end -- url or wikilink in author link;
    |firstn= also allowed to contain hyphens, spaces, apostrophes, and periods
    end
     
    table.insert( text, one )
    At the time of this writing, I had to write the 'if nil == mw.ustring.find ...' test ouside of the code editor and paste it here
    table.insert( text, sep_one )
    because the code editor gets confused between character insertion point and cursor position.
    end
     
    end
    ]]


    local count = #text / 2; -- (number of names + number of separators) divided by 2
    local function is_good_vanc_name (last, first)
    if count > 0 then
    if nil == mw.ustring.find (last, "^[A-Za-zÀ-ÖØ-öø-ƿDŽ-ɏ%-%s%']*$") or nil == mw.ustring.find (first, "^[A-Za--ÖØ-öø-ƿDŽ-ɏ%-%s%'%.]*$") then
    if count > 1 and is_set(lastauthoramp) and not etal then
    add_vanc_error ();
    text[#text-2] = " & "; -- replace last separator with ampersand text
    return false; -- not a string of latin characters; Vancouver required Romanization
    end
    end;
    text[#text] = nil; -- erase the last separator
    return true;
    end
    local result = table.concat(text) -- construct list
    if etal and 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 go a last-first list and etal so add et al.
    end
    return result, count
    end
    end


    --[[--------------------------< A N C H O R _ I D >------------------------------------------------------------
    --[[--------------------------< R E D U C E _ T O _ I N I T I A L S >------------------------------------------


    Generates a CITEREF anchor ID if we have at least one name or a dateOtherwise returns an empty string.
    Attempts to convert names to initials in support of |name-list-format=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/.


    local function anchor_id( options )
    Vancouver style requires family rank designations (Jr, II, III, etc) to be rendered as Jr, 2nd, 3rd, etc.  This form is not
    local id = table.concat( options ); -- concatenate names and year for CITEREF id
    currently supported by this code so correctly formed names like Smith JL 2nd are converted to Smith J2. See http://www.ncbi.nlm.nih.gov/books/NBK7271/box/A35085/.
    if is_set (id) then -- if concatenation is not an empty string
     
    return "CITEREF" .. id; -- add the CITEREF portion
    This function uses ustring functions because firstname initials may be any of the unicode Latin characters accepted by is_good_vanc_name ().
    else
     
    return ''; -- return an empty string; no reason to include CITEREF id in this citation
    ]]
     
    local function reduce_to_initials(first)
    if mw.ustring.match(first, "^%u%u$") then return first end; -- when first contains just two upper-case letters, nothing to do
    local initials = {}
    local i = 0; -- counter for number of initials
    for word in mw.ustring.gmatch(first, "[^%s%.%-]+") do -- names separated by spaces, hyphens, or periods
    table.insert(initials, mw.ustring.sub(word,1,1)) -- Vancouver format does not include full stops.
    i = i + 1; -- bump the counter
    if 2 <= i then break; end -- only two initials allowed in Vancouver system; if 2, quit
    end
    end
    return table.concat(initials) -- Vancouver format does not include spaces.
    end
    end


    --[[--------------------------< N A M E _ H A S _ E T A L >----------------------------------------------------
    --[[--------------------------< L I S _ P E O P L E >-------------------------------------------------------


    Evaluates the content of author and editor name parameters for variations on the theme of et al.  If found,
    Formats a list of people (e.g. authors / editors)
    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 it's previous state because it may have been set by
    previous passes through this function or by the parameters |display-authors=etal or |display-editors=etal


    ]]
    ]]


    local function name_has_etal (name, etal, nocat)
    local function list_people(control, people, etal, list_name) -- TODO: why is list_name here?  not used in this function
    local sep;
    local namesep;
    local format = control.format
    local maximum = control.maximum
    local lastauthoramp = control.lastauthoramp;
    local text = {}


    if is_set (name) then -- name can be nil in which case just return
    if 'vanc' == format then -- Vancouver-like author/editor name styling?
    local etal_pattern = "[;,]? *[\"']*%f[Ee][Ee][Tt] *[Aa][Ll][%.\"']*$" -- variations on the 'et al' theme
    sep = ','; -- name-list separator between authors is a comma
    local others_pattern = "[;,]? *%f[%a]and [Oo]thers"; -- and alternate to et al.
    namesep = ' '; -- last/first separator is a space
    else
    if name:match (etal_pattern) then -- variants on et al.
    sep = ';' -- name-list separator between authors is a semicolon
    name = name:gsub (etal_pattern, ''); -- if found, remove
    namesep = ', ' -- last/first separator is <comma><space>
    etal = true; -- set flag (may have been set previously here or by |display-authors=etal)
    end
    if not nocat then -- no categorization for |vauthors=
    add_maint_cat ('etal'); -- and add a category if not already added
    if sep:sub(-1,-1) ~= " " then sep = sep .. " " end
    end
    if is_set (maximum) and maximum < 1 then return "", 0; end -- returned 0 is for EditorCount; not used for authors
    elseif name:match (others_pattern) then -- if not 'et al.', then 'and others'?
    name = name:gsub (others_pattern, ''); -- if found, remove
    for i,person in ipairs(people) do
    etal = true; -- set flag (may have been set previously here or by |display-authors=etal)
    if is_set(person.last) then
    if not nocat then -- no categorization for |vauthors=
    local mask = person.mask
    add_maint_cat ('etal'); -- and add a category if not already added
    local one
    end
    local sep_one = sep;
    end
    if is_set (maximum) and i > maximum then
    etal = true;
    break;
    elseif (mask ~= nil) then
    local n = tonumber(mask)
    if (n ~= nil) then
    one = string.rep("&mdash;",n)
    else
    one = mask;
    sep_one = " ";
    end
    else
    one = person.last
    local first = person.first
    if 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) then -- and name is all Latin characters; corporate authors not tested
    first = reduce_to_initials(first) -- attempt to convert first name(s) to initials
    end
    end
    one = one .. namesep .. first
    end
    if is_set(person.link) and person.link ~= control.page_name then
    one = "[[" .. person.link .. "|" .. one .. "]]" -- link author/editor if this page is not the author's/editor's page
    end
    end
    table.insert( text, one )
    table.insert( text, sep_one )
    end
    end
    end
    return name, etal; --
    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
    local count = #text / 2; -- (number of names + number of separators) divided by 2
    that will cause list_people() to add the static 'et al.' text from Module:Citation/CS1/Configuration.  This keeps 'et al.' out of the
    if count > 0 then
    template's metadata.  When this occurs, the page is added to a maintenance category.
    if count > 1 and is_set(lastauthoramp) and not etal then
    text[#text-2] = " & "; -- replace last separator with ampersand text
    end
    text[#text] = nil; -- erase the last separator
    end
    local result = table.concat(text) -- construct list
    if etal and 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 go a last-first list and etal so add et al.
    end
    return result, count
    end


    ]]
    --[[--------------------------< A N C H O R _ I D >------------------------------------------------------------


    local function extract_names(args, list_name)
    Generates a CITEREF anchor ID if we have at least one name or a date. Otherwise returns an empty string.
    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 err_msg_list_name = list_name:match ("(%w+)List") .. 's list'; -- modify AuthorList or EditorList for use in error messages if necessary
    namelist is one of the contributor-, author-, or editor-name lists chosen in that order. year is Year or anchor_year.
    while true do
    last = select_one( args, cfg.aliases[list_name .. '-Last'], 'redundant_parameters', i ); -- search through args for name components beginning at 1
    first = select_one( args, cfg.aliases[list_name .. '-First'], 'redundant_parameters', i );
    link = select_one( args, cfg.aliases[list_name .. '-Link'], 'redundant_parameters', i );
    mask = select_one( args, cfg.aliases[list_name .. '-Mask'], 'redundant_parameters', i );


    last, etal = name_has_etal (last, etal, false); -- find and remove variations on et al.
    ]]
    first, etal = name_has_etal (first, etal, false); -- find and remove variations on et al.
    local function anchor_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 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


    if first and not last then -- if there is a firstn without a matching lastn
    table.insert( z.message_tail, { set_error( 'first_missing_last', {err_msg_list_name, i}, 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
    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, { set_error( 'missing_name', {err_msg_list_name, 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
    end


    -- Populates ID table from arguments using configuration settings
    --[[--------------------------< N A M E _ H A S _ E T A L >----------------------------------------------------
    local function extract_ids( args )
    local id_list = {};
    for k, v in pairs( cfg.id_handlers ) do
    v = select_one( args, v.parameters, 'redundant_parameters' );
    if is_set(v) then id_list[k] = v; end
    end
    return id_list;
    end


    --[[--------------------------< B U I L D _ I D _ L I S T >--------------------------------------------------------
    Evaluates the content of author and editor name parameters 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.


    Takes a table of IDs and turns it into a table of formatted ID outputs.
    This function never sets the flag to false but returns it's previous state because it may have been set by
    previous passes through this function or by the parameters |display-authors=etal or |display-editors=etal


    ]]
    ]]


    local function build_id_list( id_list, options )
    local function name_has_etal (name, etal, nocat)
    local new_list, handler = {};


    function fallback(k) return { __index = function(t,i) return cfg.id_handlers[k][i] end } end;
    if is_set (name) then -- name can be nil in which case just return
    local etal_pattern = "[;,]? *[\"']*%f[%a][Ee][Tt] *[Aa][Ll][%.\"']*$" -- variations on the 'et al' theme
    for k, v in pairs( id_list ) do
    local others_pattern = "[;,]? *%f[%a]and [Oo]thers"; -- and alternate to et al.
    -- fallback to read-only cfg
    handler = setmetatable( { ['id'] = v }, fallback(k) );
    if handler.mode == 'external' then
    if name:match (etal_pattern) then -- variants on et al.
    table.insert( new_list, {handler.label, external_link_id( handler ) } );
    name = name:gsub (etal_pattern, ''); -- if found, remove
    elseif handler.mode == 'internal' then
    etal = true; -- set flag (may have been set previously here or by |display-authors=etal)
    table.insert( new_list, {handler.label, internal_link_id( handler ) } );
    if not nocat then -- no categorization for |vauthors=
    elseif handler.mode ~= 'manual' then
    add_maint_cat ('etal'); -- and add a category if not already added
    error( cfg.messages['unknown_ID_mode'] );
    end
    elseif k == 'DOI' then
    elseif name:match (others_pattern) then -- if not 'et al.', then 'and others'?
    table.insert( new_list, {handler.label, doi( v, options.DoiBroken ) } );
    name = name:gsub (others_pattern, ''); -- if found, remove
    elseif k == 'ARXIV' then
    etal = true; -- set flag (may have been set previously here or by |display-authors=etal)
    table.insert( new_list, {handler.label, arxiv( v, options.Class ) } );
    if not nocat then -- no categorization for |vauthors=
    elseif k == 'ASIN' then
    add_maint_cat ('etal'); -- and add a category if not already added
    table.insert( new_list, {handler.label, amazon( v, options.ASINTLD ) } );  
    elseif k == 'LCCN' then
    table.insert( new_list, {handler.label, lccn( v ) } );
    elseif k == 'OL' then
    table.insert( new_list, {handler.label, openlibrary( v ) } );
    elseif k == 'PMC' then
    table.insert( new_list, {handler.label, pmc( v, options.Embargo ) } );
    elseif k == 'PMID' then
    table.insert( new_list, {handler.label, pmid( v ) } );
    elseif k == 'ISMN' then
    table.insert( new_list, {handler.label, ismn( v ) } );
    elseif k == 'ISSN' then
    table.insert( new_list, {handler.label, issn( v ) } );
    elseif k == 'ISBN' then
    local ISBN = internal_link_id( handler );
    if not check_isbn( v ) and not is_set(options.IgnoreISBN) then
    ISBN = ISBN .. set_error( 'bad_isbn', {}, false, " ", "" );
    end
    end
    table.insert( new_list, {handler.label, ISBN } );
    elseif k == 'USENETID' then
    table.insert( new_list, {handler.label, message_id( v ) } );
    else
    error( cfg.messages['unknown_manual_ID'] );
    end
    end
    end
    end
    return name, etal; --  
    function comp( a, b ) -- used in following table.sort()
    return a[1] < b[1];
    end
    table.sort( new_list, comp );
    for k, v in ipairs( new_list ) do
    new_list[k] = v[2];
    end
    return new_list;
    end
    end
     


    --[[--------------------------< C O I N S >--------------------------------------------------------------------
    --[[--------------------------< 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=.


    COinS metadata (see <http://ocoins.info/>) allows automated tools to parse the citation information.
    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, the page is added to a maintenance category.


    ]]
    ]]


    local function COinS(data, class)
    local function extract_names(args, list_name)
    if 'table' ~= type(data) or nil == next(data) then
    local names = {}; -- table of names
    return '';
    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 err_msg_list_name = list_name:match ("(%w+)List") .. 's list'; -- modify AuthorList or EditorList for use in error messages if necessary
    while true do
    last = select_one( args, cfg.aliases[list_name .. '-Last'], 'redundant_parameters', i ); -- search through args for name components beginning at 1
    first = select_one( args, cfg.aliases[list_name .. '-First'], 'redundant_parameters', i );
    link = select_one( args, cfg.aliases[list_name .. '-Link'], 'redundant_parameters', i );
    mask = select_one( args, cfg.aliases[list_name .. '-Mask'], 'redundant_parameters', i );
     
    last, etal = name_has_etal (last, etal, false); -- find and remove variations on et al.
    first, etal = name_has_etal (first, etal, false); -- find and remove variations on et al.
     
    if first and not last then -- if there is a firstn without a matching lastn
    table.insert( z.message_tail, { set_error( 'first_missing_last', {err_msg_list_name, i}, 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
    if is_set (link) and false == link_param_ok (link) then -- do this test here in case link is missing last
    table.insert( z.message_tail, { set_error( 'bad_paramlink', list_name:match ("(%w+)List"):lower() .. '-link' .. i )}); -- url or wikilink in author link;
    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, { set_error( 'missing_name', {err_msg_list_name, 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
    end
    local ctx_ver = "Z39.88-2004";
    return names, etal; -- all done, return our list of names
    end
    -- treat table strictly as an array with only set values.
     
    local OCinSoutput = setmetatable( {}, {
    --[[--------------------------< B U I L D _ I D _ L I S T >--------------------------------------------------------
    __newindex = function(self, key, value)
     
    if is_set(value) then
    Populates ID table from arguments using configuration settings. Loops through cfg.id_handlers and searches args for
    rawset( self, #self+1, table.concat{ key, '=', mw.uri.encode( remove_wiki_link( value ) ) } );
    any of the parameters listed in each cfg.id_handlers['...'].parameters. If found, adds the parameter and value to
    end
    the identifier list.  Emits redundant error message is more than one alias exists in args
    end
     
    });
    ]]
     
    if in_array (class, {'citation', 'conference', 'interview', 'press release'}) and is_set(data.Periodical) then
    local function extract_ids( args )
    OCinSoutput.rft_val_fmt = "info:ofi/fmt:kev:mtx:journal";
    local id_list = {}; -- list of identifiers found in args
    OCinSoutput["rft.genre"] = "article";
    for k, v in pairs( cfg.id_handlers ) do -- k is uc identifier name as index to cfg.id_handlers; e.g. cfg.id_handlers['ISBN'], v is a table
    OCinSoutput["rft.jtitle"] = data.Periodical;
    v = select_one( args, v.parameters, 'redundant_parameters' ); -- v.parameters is a table of aliases for k; here we pick one from args if present
    OCinSoutput["rft.atitle"] = data.Title;
    if is_set(v) then id_list[k] = v; end -- if found in args, add identifier to our list
    elseif in_array (class, {'arxiv', 'journal', 'news'}) then
    OCinSoutput.rft_val_fmt = "info:ofi/fmt:kev:mtx:journal";
    if 'arxiv' == class then
    OCinSoutput["rft.genre"] = "preprint"; -- cite arxiv
    else
    OCinSoutput["rft.genre"] = "article";
    end
    OCinSoutput["rft.jtitle"] = data.Periodical;
    OCinSoutput["rft.atitle"] = data.Title;
    else
    OCinSoutput.rft_val_fmt = "info:ofi/fmt:kev:mtx:book";
    if is_set (data.Chapter) then
    OCinSoutput["rft.genre"] = "bookitem";
    OCinSoutput["rft.atitle"] = data.Chapter;
    else
    OCinSoutput["rft.genre"] = "book"
    end
    OCinSoutput["rft.btitle"] = data.Title;
    end
    end
    return id_list;
    end


    OCinSoutput["rft.place"] = data.PublicationPlace;
    --[[--------------------------< B U I L D _ I D _ L I S T >--------------------------------------------------------
    OCinSoutput["rft.date"] = data.Date;
     
    OCinSoutput["rft.series"] = data.Series;
    Takes a table of IDs created by extract_ids() and turns it into a table of formatted ID outputs.
    OCinSoutput["rft.volume"] = data.Volume;
     
    OCinSoutput["rft.issue"] = data.Issue;
    inputs:
    OCinSoutput["rft.pages"] = data.Pages;
    id_list – table of identifiers built by extract_ids()
    OCinSoutput["rft.edition"] = data.Edition;
    options – table of various template parameter values used to modify some manually handled identifiers
    OCinSoutput["rft.pub"] = data.PublisherName;
     
    ]]
     
    local function build_id_list( id_list, options )
    local new_list, handler = {};
     
    function fallback(k) return { __index = function(t,i) return cfg.id_handlers[k][i] end } end;
    for k, v in pairs( data.ID_list ) do
    for k, v in pairs( id_list ) do -- k is uc identifier name as index to cfg.id_handlers; e.g. cfg.id_handlers['ISBN'], v is a table
    local id, value = cfg.id_handlers[k].COinS;
    -- fallback to read-only cfg
    if k == 'ISBN' then value = clean_isbn( v ); else value = v; end
    handler = setmetatable( { ['id'] = v }, fallback(k) );
    if string.sub( id or "", 1, 4 ) == 'info' then
    OCinSoutput["rft_id"] = table.concat{ id, "/", v };
    if handler.mode == 'external' then
    table.insert( new_list, {handler.label, external_link_id( handler ) } );
    elseif handler.mode == 'internal' then
    table.insert( new_list, {handler.label, internal_link_id( handler ) } );
    elseif handler.mode ~= 'manual' then
    error( cfg.messages['unknown_ID_mode'] );
    elseif k == 'DOI' then
    table.insert( new_list, {handler.label, doi( v, options.DoiBroken ) } );
    elseif k == 'ARXIV' then
    table.insert( new_list, {handler.label, arxiv( v, options.Class ) } );
    elseif k == 'ASIN' then
    table.insert( new_list, {handler.label, amazon( v, options.ASINTLD ) } );  
    elseif k == 'LCCN' then
    table.insert( new_list, {handler.label, lccn( v ) } );
    elseif k == 'OL' or k == 'OLA' then
    table.insert( new_list, {handler.label, openlibrary( v ) } );
    elseif k == 'PMC' then
    table.insert( new_list, {handler.label, pmc( v, options.Embargo ) } );
    elseif k == 'PMID' then
    table.insert( new_list, {handler.label, pmid( v ) } );
    elseif k == 'ISMN' then
    table.insert( new_list, {handler.label, ismn( v ) } );
    elseif k == 'ISSN' then
    table.insert( new_list, {handler.label, issn( v ) } );
    elseif k == 'ISBN' then
    local ISBN = internal_link_id( handler );
    if not check_isbn( v ) and not is_set(options.IgnoreISBN) then
    ISBN = ISBN .. set_error( 'bad_isbn', {}, false, " ", "" );
    end
    table.insert( new_list, {handler.label, ISBN } );
    elseif k == 'USENETID' then
    table.insert( new_list, {handler.label, message_id( v ) } );
    else
    else
    OCinSoutput[ id ] = value;
    error( cfg.messages['unknown_manual_ID'] );
    end
    end
    end
    end
    local last, first;
    function comp( a, b ) -- used in following table.sort()
    for k, v in ipairs( data.Authors ) do
    return a[1] < b[1];
    last, first = v.last, v.first;
    end
    if k == 1 then -- for the first author name only
    if is_set(last)  and is_set(first) then -- set these COinS values if |first= and |last= specify the first author name
    table.sort( new_list, comp );
    OCinSoutput["rft.aulast"] = last;
    for k, v in ipairs( new_list ) do
    OCinSoutput["rft.aufirst"] = first;
    new_list[k] = v[2];
    elseif is_set(last) then
    OCinSoutput["rft.au"] = last; -- otherwise use this form for the first name
    end
    else -- for all other authors
    if is_set(last) and is_set(first) then
    OCinSoutput["rft.au"] = table.concat{ last, ", ", first };
    elseif is_set(last) then
    OCinSoutput["rft.au"] = last;
    end
    end
    end
    end
    OCinSoutput.rft_id = data.URL;
    OCinSoutput.rfr_id = table.concat{ "info:sid/", mw.site.server:match( "[^/]*$" ), ":", data.RawPage };
    OCinSoutput = setmetatable( OCinSoutput, nil );
    -- sort with version string always first, and combine.
    return new_list;
    table.sort( OCinSoutput );
    table.insert( OCinSoutput, 1, "ctx_ver=" .. ctx_ver );  -- such as "Z39.88-2004"
    return table.concat(OCinSoutput, "&");
    end
    end
     


    --[[--------------------------< C O I N S >--------------------------------------------------------------------


    --[[--------------------------< G E T _ I S O 6 3 9 _ C O D E >------------------------------------------------
    COinS metadata (see <http://ocoins.info/>) allows automated tools to parse the citation information.


    Validates language names provided in |language= parameter if not an ISO639-1 code.  Handles the special case that is Norwegian where
    ]]
    ISO639-1 code 'no' is mapped to language name 'Norwegian Bokmål' by Extention:CLDR.


    Returns the language name and associated ISO639-1 code.  Because case of the source may be incorrect or different from the case that Wikimedia
    local function COinS(data, class)
    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
    if 'table' ~= type(data) or nil == next(data) then
    with the code.  When there is no match, we return the original language name string.
    return '';
     
    mw.language.fetchLanguageNames() will return a list of languages that aren't part of ISO639-1. Names that aren't ISO639-1 but that are included
    in the list will be found if that name is provided in the |language= parameter.  For example, if |language=Samaritan Aramaic, that name will be
    found with the associated code 'sam', not an ISO639-1 code.  When names are found and the associated code is not two characters, this function
    returns only the Wikimedia language name.
     
    Adapted from code taken from Module:Check ISO 639-1.
     
    ]]
     
    local function get_iso639_code (lang)
    if 'norwegian' == lang:lower() then -- special case related to Wikimedia remap of code 'no' at Extension:CLDR
    return 'Norwegian', 'no'; -- Make sure rendered version is properly capitalized
    end
    end
    local languages = mw.language.fetchLanguageNames('en', 'all') -- get a list of language names known to Wikimedia
    local ctx_ver = "Z39.88-2004";
    -- ('all' is required for North Ndebele, South Ndebele, and Ojibwa)
    local langlc = mw.ustring.lower(lang); -- lower case version for comparisons
    for code, name in pairs(languages) do -- scan the list to see if we can find our language
    -- treat table strictly as an array with only set values.
    if langlc == mw.ustring.lower(name) then
    local OCinSoutput = setmetatable( {}, {
    if 2 ~= code:len() then -- ISO639-1 codes only
    __newindex = function(self, key, value)
    return name; -- so return the name but not the code
    if is_set(value) then
    rawset( self, #self+1, table.concat{ key, '=', mw.uri.encode( remove_wiki_link( value ) ) } );
    end
    end
    return name, code; -- found it, return name to ensure proper capitalization and the ISO639-1 code
    end
    end
    end
    });
    return lang; -- not valid language; return language in original case and nil for ISO639-1 code
    end
    if in_array (class, {'arxiv', 'journal', 'news'}) or (in_array (class, {'conference', 'interview', 'map', 'press release', 'web'}) and is_set(data.Periodical)) or
     
    ('citation' == class and is_set(data.Periodical) and not is_set (data.Encyclopedia)) then
    --[[--------------------------< L A N G U A G E _ P A R A M E T E R >------------------------------------------
    OCinSoutput.rft_val_fmt = "info:ofi/fmt:kev:mtx:journal"; -- journal metadata identifier
    if 'arxiv' == class then -- set genre according to the type of citation template we are rendering
    OCinSoutput["rft.genre"] = "preprint"; -- cite arxiv
    elseif 'conference' == class then
    OCinSoutput["rft.genre"] = "conference"; -- cite conference (when Periodical set)
    elseif 'web' == class then
    OCinSoutput["rft.genre"] = "unknown"; -- cite web (when Periodical set)
    else
    OCinSoutput["rft.genre"] = "article"; -- journal and other 'periodical' articles
    end
    OCinSoutput["rft.jtitle"] = data.Periodical; -- journal only
    if is_set (data.Map) then
    OCinSoutput["rft.atitle"] = data.Map; -- for a map in a periodical
    else
    OCinSoutput["rft.atitle"] = data.Title; -- all other 'periodical' article titles
    end
    -- these used onlu for periodicals
    OCinSoutput["rft.ssn"] = data.Season; -- keywords: winter, spring, summer, fall
    OCinSoutput["rft.chron"] = data.Chron; -- free-form date components
    OCinSoutput["rft.volume"] = data.Volume; -- does not apply to books
    OCinSoutput["rft.issue"] = data.Issue;
    OCinSoutput["rft.pages"] = data.Pages; -- also used in book metadata


    Get language name from ISO639-1 code value provided. If a code is valid use the returned name; if not, then use the value that was provided with the language parameter.
    elseif 'thesis' ~= class then -- all others except cite thesis are treated as 'book' metadata; genre distinguishes
     
    OCinSoutput.rft_val_fmt = "info:ofi/fmt:kev:mtx:book"; -- book metadata identifier
    There is an exception. There are three ISO639-1 codes for Norewegian language variants. There are two official variants: Norwegian Bokmål (code 'nb') and
    if 'report' == class or 'techreport' == class then -- cite report and cite techreport
    Norwegian Nynorsk (code 'nn').  The third, code 'no', is defined by ISO639-1 as 'Norwegian' though in Norway this is pretty much meaningless. However, it appears
    OCinSoutput["rft.genre"] = "report";
    that on enwiki, editors are for the most part unaware of the nb and nn variants (compare page counts for these variants at Category:Articles with non-English-language external links.
    elseif 'conference' == class then -- cite conference when Periodical not set
     
    OCinSoutput["rft.genre"] = "conference";
    Because Norwegian Bokmål is the most common language variant, Media wiki has been modified to return Norwegian Bokmål for ISO639-1 code 'no'. Here we undo that and
    elseif in_array (class, {'book', 'citation', 'encyclopaedia', 'interview', 'map'}) then
    return 'Norwegian' when editors use |language=no. We presume that editors don't know about the variants or can't descriminate between them.
    if is_set (data.Chapter) then
     
    OCinSoutput["rft.genre"] = "bookitem";
    See Help talk:Citation Style_1#An ISO 639-1 language name test
    OCinSoutput["rft.atitle"] = data.Chapter; -- book chapter, encyclopedia article, interview in a book, or map title
     
    else
    When |language= contains a valid ISO639-1 code, the page is assigned to the category for that code: Category:Norwegian-language sources (no) if
    if 'map' == class or 'interview' == class then
    the page is a mainspace page and the ISO639-1 code is not 'en'. Similarly, if the  parameter is |language=Norwegian, it will be categorized in the same way.
    OCinSoutput["rft.genre"] = 'unknown'; -- standalone map or interview
     
    else
    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.
    OCinSoutput["rft.genre"] = 'book'; -- book and encyclopedia
    end
    end
    else --{'audio-visual', 'AV-media-notes', 'DVD-notes', 'episode', 'interview', 'mailinglist', 'map', 'newsgroup', 'podcast', 'press release', 'serial', 'sign', 'speech', 'web'}
    OCinSoutput["rft.genre"] = "unknown";
    end
    OCinSoutput["rft.btitle"] = data.Title; -- book only
    OCinSoutput["rft.place"] = data.PublicationPlace; -- book only
    OCinSoutput["rft.series"] = data.Series; -- book only
    OCinSoutput["rft.pages"] = data.Pages; -- book, journal
    OCinSoutput["rft.edition"] = data.Edition; -- book only
    OCinSoutput["rft.pub"] = data.PublisherName; -- book and dissertation
    else -- cite thesis
    OCinSoutput.rft_val_fmt = "info:ofi/fmt:kev:mtx:dissertation"; -- dissertation metadata identifier
    OCinSoutput["rft.title"] = data.Title; -- dissertation (also patent but that is not yet supported)
    OCinSoutput["rft.degree"] = data.Degree; -- dissertation only
    OCinSoutput['rft.inst'] = data.PublisherName; -- book and dissertation
    end
    -- and now common parameters (as much as possible)
    OCinSoutput["rft.date"] = data.Date; -- book, journal, dissertation
    for k, v in pairs( data.ID_list ) do -- what to do about these? For now assume that they are common to all?
    if k == 'ISBN' then v = clean_isbn( v ) end
    local id = cfg.id_handlers[k].COinS;
    if string.sub( id or "", 1, 4 ) == 'info' then -- for ids that are in the info:registry
    OCinSoutput["rft_id"] = table.concat{ id, "/", v };
    elseif string.sub (id or "", 1, 3 ) == 'rft' then -- for isbn, issn, eissn, etc that have defined COinS keywords
    OCinSoutput[ id ] = v;
    elseif id then -- when cfg.id_handlers[k].COinS is not nil
    OCinSoutput["rft_id"] = table.concat{ cfg.id_handlers[k].prefix, v }; -- others; provide a url
    end
    end


    --[[
    for k, v in pairs( data.ID_list ) do -- what to do about these? For now assume that they are common to all?
    local id, value = cfg.id_handlers[k].COinS;
    if k == 'ISBN' then value = clean_isbn( v ); else value = v; end
    if string.sub( id or "", 1, 4 ) == 'info' then
    OCinSoutput["rft_id"] = table.concat{ id, "/", v };
    else
    OCinSoutput[ id ] = value;
    end
    end
    ]]
    ]]
    local last, first;
    for k, v in ipairs( data.Authors ) do
    last, first = v.last, v.first;
    if k == 1 then -- for the first author name only
    if is_set(last)  and is_set(first) then -- set these COinS values if |first= and |last= specify the first author name
    OCinSoutput["rft.aulast"] = last; -- book, journal, dissertation
    OCinSoutput["rft.aufirst"] = first; -- book, journal, dissertation
    elseif is_set(last) then
    OCinSoutput["rft.au"] = last; -- book, journal, dissertation -- otherwise use this form for the first name
    end
    else -- for all other authors
    if is_set(last) and is_set(first) then
    OCinSoutput["rft.au"] = table.concat{ last, ", ", first }; -- book, journal, dissertation
    elseif is_set(last) then
    OCinSoutput["rft.au"] = last; -- book, journal, dissertation
    end
    end
    end
    OCinSoutput.rft_id = data.URL;
    OCinSoutput.rfr_id = table.concat{ "info:sid/", mw.site.server:match( "[^/]*$" ), ":", data.RawPage };
    OCinSoutput = setmetatable( OCinSoutput, nil );
    -- sort with version string always first, and combine.
    table.sort( OCinSoutput );
    table.insert( OCinSoutput, 1, "ctx_ver=" .. ctx_ver );  -- such as "Z39.88-2004"
    return table.concat(OCinSoutput, "&");
    end


    local function language_parameter (lang)
    local code; -- the ISO639-1 two character 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=


    names_table = mw.text.split (lang, '%s*,%s*'); -- names should be a comma separated list
    --[[--------------------------< G E T _ I S O 6 3 9 _ C O D E >------------------------------------------------


    for _, lang in ipairs (names_table) do -- reuse lang
    Validates language names provided in |language= parameter if not an ISO639-1 code.  Handles the special case that is Norwegian where
    ISO639-1 code 'no' is mapped to language name 'Norwegian Bokmål' by Extention:CLDR.


    if 2 == lang:len() then -- ISO639-1 language code are 2 characters (fetchLanguageName also supports 3 character codes)
    Returns the language name and associated ISO639-1 code.  Because case of the source may be incorrect or different from the case that Wikimedia
    name = mw.language.fetchLanguageName( lang:lower(), "en" ); -- get ISO 639-1 language name if Language is a proper code
    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
    end
    with the code. When there is no match, we return the original language name string.
    if is_set (name) then -- if Language specified a valid ISO639-1 code
    code = lang:lower(); -- save it
    else
    name, code = get_iso639_code (lang); -- attempt to get code from name (assign name here so that we are sure of proper capitalization)
    end
    if is_set (code) then
    if 'no' == code then name = 'Norwegian' end; -- override wikimedia when code is 'no'
    if 'en' ~= code then -- English not the language
    add_prop_cat ('foreign_lang_source', {name, code})
    end
    else
    add_maint_cat ('unknown_lang'); -- add maint category if not already added
    end
    table.insert (language_list, name);
    name = ''; -- so we can reuse it
    end
    code = #language_list -- reuse code as number of languages in the list
    if 2 >= code then
    name = table.concat (language_list, ' and ') -- insert '<space>and<space>' between two language names
    elseif 2 < code then
    language_list[code] = 'and ' .. language_list[code]; -- prepend last name with 'and<space>'
    name = table.concat (language_list, ', ') -- and concatenate with '<comma><space>' separators
    end
    if 'English' == name then
    return ''; -- if one language and that language is English return an enpty string (no annotation)
    end
    return (" " .. wrap_msg ('language', name)); -- otherwise wrap with '(in ...)'
    end


    --[[--------------------------< S E T _ C S 1 _ S T Y L E >----------------------------------------------------
    mw.language.fetchLanguageNames() will return a list of languages that aren't part of ISO639-1. Names that aren't ISO639-1 but that are included
    in the list will be found if that name is provided in the |language= parameter.  For example, if |language=Samaritan Aramaic, that name will be
    found with the associated code 'sam', not an ISO639-1 code.  When names are found and the associated code is not two characters, this function
    returns only the Wikimedia language name.


    Set style settings for CS1 citation templates. Returns separator and postscript settings
    Adapted from code taken from Module:Check ISO 639-1.


    ]]
    ]]


    local function set_cs1_style (ps)
    local function get_iso639_code (lang)
    if not is_set (ps) then -- unless explicitely set to something
    if 'norwegian' == lang:lower() then -- special case related to Wikimedia remap of code 'no' at Extension:CLDR
    ps = '.'; -- terminate the rendered citation with a period
    return 'Norwegian', 'no'; -- Make sure rendered version is properly capitalized
    end
    local languages = mw.language.fetchLanguageNames('en', 'all') -- get a list of language names known to Wikimedia
    -- ('all' is required for North Ndebele, South Ndebele, and Ojibwa)
    local langlc = mw.ustring.lower(lang); -- lower case version for comparisons
    for code, name in pairs(languages) do -- scan the list to see if we can find our language
    if langlc == mw.ustring.lower(name) then
    if 2 ~= code:len() then -- ISO639-1 codes only
    return name; -- so return the name but not the code
    end
    return name, code; -- found it, return name to ensure proper capitalization and the ISO639-1 code
    end
    end
    end
    return '.', ps; -- separator is a full stop
    return lang; -- not valid language; return language in original case and nil for ISO639-1 code
    end
    end


    --[[--------------------------< S E T _ C S 2 _ S T Y L E >----------------------------------------------------
    --[[--------------------------< L A N G U A G E _ P A R A M E T E R >------------------------------------------
     
    Get language name from ISO639-1 code value provided.  If a code is valid use the returned name; if not, then use the value that was provided with the language parameter.
     
    There is an exception.  There are three ISO639-1 codes for Norewegian language variants.  There are two official variants: Norwegian Bokmål (code 'nb') and
    Norwegian Nynorsk (code 'nn').  The third, code 'no',  is defined by ISO639-1 as 'Norwegian' though in Norway this is pretty much meaningless.  However, it appears
    that on enwiki, editors are for the most part unaware of the nb and nn variants (compare page counts for these variants at Category:Articles with non-English-language external links.


    Set style settings for CS2 citation templates. Returns separator, postscript, ref settings
    Because Norwegian Bokmål is the most common language variant, Media wiki has been modified to return Norwegian Bokmål for ISO639-1 code 'no'. Here we undo that and
    return 'Norwegian' when editors use |language=no.  We presume that editors don't know about the variants or can't descriminate between them.


    ]]
    See Help talk:Citation Style_1#An ISO 639-1 language name test


    local function set_cs2_style (ps, ref)
    When |language= contains a valid ISO639-1 code, the page is assigned to the category for that code: Category:Norwegian-language sources (no) if
    if not is_set (ps) then -- if |postscript= has not been set, set cs2 default
    the page is a mainspace page and the ISO639-1 code is not 'en'.  Similarly, if the  parameter is |language=Norwegian, it will be categorized in the same way.
    ps = ''; -- make sure it isn't nil
    end
    if not is_set (ref) then -- if |ref= is not set
    ref = "harv"; -- set default |ref=harv
    end
    return ',', ps, ref; -- separator is a comma
    end


    --[[--------------------------< G E T _ S E T T I N G S _ F R O M _ C I T E _ C L A S S >----------------------
    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.
     
    When |mode= is not set or when its value is invalid, use config.CitationClass and parameter values to establish
    rendered style.


    ]]
    ]]


    local function get_settings_from_cite_class (ps, ref, cite_class)
    local function language_parameter (lang)
    local sep;
    local code; -- the ISO639-1 two character code
    if (cite_class == "citation") then -- for citation templates (CS2)
    local name; -- the language name
    sep, ps, ref = set_cs2_style (ps, ref);
    local language_list = {}; -- table of language names to be rendered
    else -- not a citation template so CS1
    local names_table = {}; -- table made from the value assigned to |language=
    sep, ps = set_cs1_style (ps);
    end


    return sep, ps, ref -- return them all
    names_table = mw.text.split (lang, '%s*,%s*'); -- names should be a comma separated list
    end


    --[[--------------------------< S E T _ S T Y L E >------------------------------------------------------------
    for _, lang in ipairs (names_table) do -- reuse lang


    Establish basic style settings to be used when rendering the citation.  Uses |mode= if set and valid or uses
    if lang:match ('^%a%a%-') then -- strip ietf language tags from code
    config.CitationClass from the template's #invoke: to establish style.
    lang = lang:match ('(%a%a)%-') -- keep only 639-1 code portion to lang; TODO: do something with 3166 alpha 2 country code?
     
    end
    ]]
    if 2 == lang:len() then -- ISO639-1 language code are 2 characters (fetchLanguageName also supports 3 character codes)
     
    name = mw.language.fetchLanguageName( lang:lower(), "en" ); -- get ISO 639-1 language name if Language is a proper code
    local function set_style (mode, ps, ref, cite_class)
    end
    local sep;
    if 'cs2' == mode then -- if this template is to be rendered in CS2 (citation) style
    if is_set (name) then -- if Language specified a valid ISO639-1 code
    sep, ps, ref = set_cs2_style (ps, ref);
    code = lang:lower(); -- save it
    elseif 'cs1' == mode then -- if this template is to be rendered in CS1 (cite xxx) style
    else
    sep, ps = set_cs1_style (ps);
    name, code = get_iso639_code (lang); -- attempt to get code from name (assign name here so that we are sure of proper capitalization)
    else -- anything but cs1 or cs2
    end
    sep, ps, ref = get_settings_from_cite_class (ps, ref, cite_class); -- get settings based on the template's CitationClass
    end
    if is_set (code) then
    if 'none' == ps:lower() then -- if assigned value is 'none' then
    if 'no' == code then name = 'Norwegian' end; -- override wikimedia when code is 'no'
    ps = ''; -- set to empty string
    if 'en' ~= code then -- English not the language
    add_prop_cat ('foreign_lang_source', {name, code})
    end
    else
    add_maint_cat ('unknown_lang'); -- add maint category if not already added
    end
    table.insert (language_list, name);
    name = ''; -- so we can reuse it
    end
    end
    return sep, ps, ref
    code = #language_list -- reuse code as number of languages in the list
    end
    if 2 >= code then
     
    name = table.concat (language_list, ' and ') -- insert '<space>and<space>' between two language names
    --[=[-------------------------< I S _ P D F >------------------------------------------------------------------
    elseif 2 < code then
    language_list[code] = 'and ' .. language_list[code]; -- prepend last name with 'and<space>'
    name = table.concat (language_list, ', ') -- and concatenate with '<comma><space>' separators
    end
    if 'English' == name then
    return ''; -- if one language and that language is English return an empty string (no annotation)
    end
    return (" " .. wrap_msg ('language', name)); -- otherwise wrap with '(in ...)'
    end


    Determines if a url has the file extension that is one of the pdf file extensions used by [[MediaWiki:Common.css]] when
    --[[--------------------------< S E T _ C S 1 _ S T Y L E >----------------------------------------------------
    applying the pdf icon to external links.


    returns true if file extension is one of the recognized extension, else false
    Set style settings for CS1 citation templates. Returns separator and postscript settings


    ]=]
    ]]


    local function is_pdf (url)
    local function set_cs1_style (ps)
    return url:match ('%.pdf[%?#]?') or url:match ('%.PDF[%?#]?');
    if not is_set (ps) then -- unless explicitely set to something
    ps = '.'; -- terminate the rendered citation with a period
    end
    return '.', ps; -- separator is a full stop
    end
    end


    --[[--------------------------< S T Y L E _ F O R M A T >------------------------------------------------------
    --[[--------------------------< S E T _ C S 2 _ S T Y L E >----------------------------------------------------


    Applies css style to |format=, |chapter-format=, etc.  Also emits an error message if the format parameter does
    Set style settings for CS2 citation templates. Returns separator, postscript, ref settings
    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)
    local function set_cs2_style (ps, ref)
    if is_set (format) then
    if not is_set (ps) then -- if |postscript= has not been set, set cs2 default
    format = wrap_style ('format', format); -- add leading space, parenthases, resize
    ps = ''; -- make sure it isn't nil
    if not is_set (url) then
    end
    format = format .. set_error( 'format_missing_url', {fmt_param, url_param} ); -- add an error message
    if not is_set (ref) then -- if |ref= is not set
    end
    ref = "harv"; -- set default |ref=harv
    elseif is_pdf (url) then -- format is not set so if url is a pdf file then
    format = wrap_style ('format', 'PDF'); -- set format to pdf
    else
    format = ''; -- empty string for concatenation
    end
    end
    return format;
    return ',', ps, ref; -- separator is a comma
    end
    end


    --[[--------------------------< G E T _ D I S P L A Y _ A U T H O R S _ E D I T O R S >------------------------
    --[[--------------------------< G E T _ S E T T I N G S _ F R O M _ C I T E _ C L A S S >----------------------
     
    When |mode= is not set or when its value is invalid, use config.CitationClass and parameter values to establish
    rendered style.
     
    ]]


    Returns a number that may or may not limit the length of the author or editor name lists.
    local function get_settings_from_cite_class (ps, ref, cite_class)
    local sep;
    if (cite_class == "citation") then -- for citation templates (CS2)
    sep, ps, ref = set_cs2_style (ps, ref);
    else -- not a citation template so CS1
    sep, ps = set_cs1_style (ps);
    end


    When the value assigned to |display-authors= is a number greater than or equal to zero, return the number and
    return sep, ps, ref -- return them all
    the previous state of the 'etal' flag (false by default but may have been set to true if the name list contains
    end
    some variant of the text 'et al.').


    When the value assigned to |display-authors= is the keyword 'etal', return a number that is one greater than the
    --[[--------------------------< S E T _ S T Y L E >------------------------------------------------------------
    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.
    Establish basic style settings to be used when rendering the citation.  Uses |mode= if set and valid or uses
    config.CitationClass from the template's #invoke: to establish style.


    ]]
    ]]


    local function get_display_authors_editors (max, count, list_name, etal)
    local function set_style (mode, ps, ref, cite_class)
    if is_set (max) then
    local sep;
    if 'etal' == max:lower():gsub("[ '%.]", '') then -- the :gsub() portion makes 'etal' from a variety of 'et al.' spellings and stylings
    if 'cs2' == mode then -- if this template is to be rendered in CS2 (citation) style
    max = count + 1; -- number of authors + 1 so display all author name plus et al.
    sep, ps, ref = set_cs2_style (ps, ref);
    etal = true; -- overrides value set by extract_names()
    elseif 'cs1' == mode then -- if this template is to be rendered in CS1 (cite xxx) style
    elseif max:match ('^%d+$') then -- if is a string of numbers
    sep, ps = set_cs1_style (ps);
    max = tonumber (max); -- make it a number
    else -- anything but cs1 or cs2
    if max >= count and 'authors' == list_name then -- AUTHORS ONLY -- if |display-xxxxors= value greater than or equal to number of authors/editors
    sep, ps, ref = get_settings_from_cite_class (ps, ref, cite_class); -- get settings based on the template's CitationClass
    add_maint_cat ('disp_auth_ed', list_name);
    end
    end
    if 'none' == ps:lower() then -- if assigned value is 'none' then
    else -- not a valid keyword or number
    ps = ''; -- set to empty string
    table.insert( z.message_tail, { set_error( 'invalid_param_val', {'display-' .. list_name, max}, true ) } ); -- add error message
    max = nil; -- unset
    end
    elseif 'authors' == list_name then -- AUTHORS ONLY need to clear implicit et al category
    max = count + 1; -- number of authors + 1
    end
    end
    return max, etal;
    return sep, ps, ref
    end
    end


    --[[--------------------------< E X T R A _ T E X T _ I N _ P A G E _ C H E C K >------------------------------
    --[=[-------------------------< I S _ P D F >------------------------------------------------------------------


    Adds page to Category:CS1 maint: extra text if |page= or |pages= has what appears to be some form of p. or pp.  
    Determines if a url has the file extension that is one of the pdf file extensions used by [[MediaWiki:Common.css]] when
    abbreviation in the first characters of the parameter content.
    applying the pdf icon to external links.


    check Page and Pages for extraneous p, p., pp, and pp. at start of parameter value:
    returns true if file extension is one of the recognized extension, else false
    good pattern: '^P[^%.P%l]' matches when |page(s)= begins PX or P# but not Px where x and X are letters and # is a dgiit
    bad pattern: '^[Pp][Pp]' matches matches when |page(s)= begins pp or pP or Pp or PP


    ]]
    ]=]


    local function extra_text_in_page_check (page, nopp)
    local function is_pdf (url)
    -- local good_pattern = '^P[^%.P%l]';
    return url:match ('%.pdf[%?#]?') or url:match ('%.PDF[%?#]?');
    local good_pattern = '^P[^%.Pp]'; -- ok to begin with uppercase P: P7 (pg 7 of section P) but not p123 (page 123) TODO: add Gg for PG or Pg?
    end
    -- local bad_pattern = '^[Pp][Pp]';
     
    local bad_pattern = '^[Pp]?[Pp]%.?[ %d]';
    --[[--------------------------< 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.


    if is_set (nopp) then -- don't bother checking if |nopp= is set
    ]]
    return;
    end


    if not page:match (good_pattern) and (page:match (bad_pattern) or  page:match ('^[Pp]ages?')) then
    local function style_format (format, url, fmt_param, url_param)
    add_maint_cat ('extra_text');
    if is_set (format) then
    format = wrap_style ('format', format); -- add leading space, parenthases, resize
    if not is_set (url) then
    format = format .. set_error( '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 = wrap_style ('format', 'PDF'); -- set format to pdf
    else
    format = ''; -- empty string for concatenation
    end
    end
    -- if Page:match ('^[Pp]?[Pp]%.?[ %d]') or  Page:match ('^[Pp]ages?[ %d]') or
    return format;
    -- Pages:match ('^[Pp]?[Pp]%.?[ %d]') or  Pages:match ('^[Pp]ages?[ %d]') then
    -- add_maint_cat ('extra_text');
    -- end
    end
    end


    --[[--------------------------< G E T _ D I S P L A Y _ A U T H O R S _ E D I T O R S >------------------------


    --[[--------------------------< P A R S E _ V A U T H O R S _ V E D I T O R S >--------------------------------
    Returns a number that may or may not limit the length of the author or editor name lists.


    This function extracts author / editor names from |vauthors= or |veditors= and finds matching |xxxxor-maskn= and
    When the value assigned to |display-authors= is a number greater than or equal to zero, return the number and
    |xxxxor-linkn= in args.  It then returns a table of assembled names just as extract_names() does.
    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.').


    Author / editor names in |vauthors= or |veditors= must be in Vancouver system style. Corporate or institutional names
    When the value assigned to |display-authors= is the keyword 'etal', return a number that is one greater than the
    may sometimes be required and because such names will often fail the is_good_vanc_name() and other format compliance
    number of authors in the list and set the 'etal' flag true. This will cause the list_people() to display all of
    tests, are wrapped in doubled paranethese ((corporate name)) to suppress the format tests.
    the names in the name list followed by 'et al.'


    This function sets the vancouver error when a reqired comma is missing and when there is a space between an author's initials.
    In all other cases, returns nil and the previous state of the 'etal' flag.


    ]]
    ]]


    local function parse_vauthors_veditors (args, vparam, list_name)
    local function get_display_authors_editors (max, count, list_name, etal)
    local names = {}; -- table of names assembled from |vauthors=, |author-maskn=, |author-linkn=
    if is_set (max) then
    local v_name_table = {};
    if 'etal' == max:lower():gsub("[ '%.]", '') then -- the :gsub() portion makes 'etal' from a variety of 'et al.' spellings and stylings
    local etal = false; -- return value set to true when we find some form of et al. vauthors parameter
    max = count + 1; -- number of authors + 1 so display all author name plus et al.
    local last, first, link, mask;
    etal = true; -- overrides value set by extract_names()
    local corporate = false;
    elseif max:match ('^%d+$') then -- if is a string of numbers
    max = tonumber (max); -- make it a number
    if max >= count and 'authors' == list_name then -- AUTHORS ONLY -- if |display-xxxxors= value greater than or equal to number of authors/editors
    add_maint_cat ('disp_auth_ed', list_name);
    end
    else -- not a valid keyword or number
    table.insert( z.message_tail, { set_error( 'invalid_param_val', {'display-' .. list_name, max}, true ) } ); -- add error message
    max = nil; -- unset
    end
    elseif 'authors' == list_name then -- AUTHORS ONLY need to clear implicit et al category
    max = count + 1; -- number of authors + 1
    end
    return max, etal;
    end


    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)
    --[[--------------------------< E X T R A _ T E X T _ I N _ P A G E _ C H E C K >------------------------------
    if vparam:find ('%[%[') or vparam:find ('%]%]') then -- no wikilinking vauthors names
    add_vanc_error ();
    end
    v_name_table = mw.text.split(vparam, "%s*,%s*") -- names are separated by commas


    for i, v_name in ipairs(v_name_table) do
    Adds page to Category:CS1 maint: extra text if |page= or |pages= has what appears to be some form of p. or pp.  
    if v_name:match ('^%(%(.+%)%)$') then -- corporate authors are wrapped in doubled parenthese to supress vanc formatting and error detection
    abbreviation in the first characters of the parameter content.
    first = ''; -- set to empty string for concatenation and because it may have been set for previous author/editor
    last = v_name:match ('^%(%((.+)%)%)$')
    corporate = true;
    elseif string.find(v_name, "%s") then
        lastfirstTable = {}
        lastfirstTable = mw.text.split(v_name, "%s")
        first = table.remove(lastfirstTable); -- removes and returns value of last element in table which should be author intials
        last  = table.concat(lastfirstTable, " ") -- returns a string that is the concatenation of all other names that are not initials
        if mw.ustring.match (last, '%a+%s+%u+%s+%a+') or mw.ustring.match (v_name, ' %u %u$') then
    add_vanc_error (); -- matches last II last; the case when a comma is missing or a space between two intiials
    end
    else
    first = ''; -- set to empty string for concatenation and because it may have been set for previous author/editor
    last = v_name; -- last name or single corporate name?  Doesn't support multiword corporate names? do we need this?
    end
    if is_set (first) and not mw.ustring.match (first, "^%u?%u$") then -- first shall contain one or two upper-case letters, nothing else
    add_vanc_error ();
    end
    -- this from extract_names ()
    link = select_one( args, cfg.aliases[list_name .. '-Link'], 'redundant_parameters', i );
    mask = select_one( args, cfg.aliases[list_name .. '-Mask'], '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 >------------------------
    check Page and Pages for extraneous p, p., pp, and pp. at start of parameter value:
    good pattern: '^P[^%.P%l]' matches when |page(s)= begins PX or P# but not Px where x and X are letters and # is a dgiit
    bad pattern: '^[Pp][Pp]' matches matches when |page(s)= begins pp or pP or Pp or PP
     
    ]]
     
    local function extra_text_in_page_check (page)
    -- local good_pattern = '^P[^%.P%l]';
    local good_pattern = '^P[^%.Pp]'; -- ok to begin with uppercase P: P7 (pg 7 of section P) but not p123 (page 123) TODO: add Gg for PG or Pg?
    -- local bad_pattern = '^[Pp][Pp]';
    local bad_pattern = '^[Pp]?[Pp]%.?[ %d]';
     
    if not page:match (good_pattern) and (page:match (bad_pattern) or  page:match ('^[Pp]ages?')) then
    add_maint_cat ('extra_text');
    end
    -- if Page:match ('^[Pp]?[Pp]%.?[ %d]') or  Page:match ('^[Pp]ages?[ %d]') or
    -- Pages:match ('^[Pp]?[Pp]%.?[ %d]') or  Pages:match ('^[Pp]ages?[ %d]') then
    -- add_maint_cat ('extra_text');
    -- end
    end


    Select one of |authors=, |authorn= / |lastn / firstn=, or |vauthors= as the source of the author name list or
    select one of |editors=, |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 and
    --[[--------------------------< P A R S E _ V A U T H O R S _ V E D I T O R S >--------------------------------
    similarly, |editorn= (and aliases) highest and |editors= lowest


    When looking for |authorn= / |editorn= parameters, test |xxxxor1= and |xxxxor2= (and all of their aliases); stops after the second
    This function extracts author / editor names from |vauthors= or |veditors= and finds matching |xxxxor-maskn= and
    test which mimicks the test used in extract_names() when looking for a hole in the author name listThere may be a better
    |xxxxor-linkn= in argsIt then returns a table of assembled names just as extract_names() does.
    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.
    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 paranethese ((corporate name)) to suppress the format tests.


    In this function, vxxxxors = vauthors or veditors; xxxxors = authors or editors as appropriate.
    This function sets the vancouver error when a reqired comma is missing and when there is a space between an author's initials.


    ]]
    ]]


    local function select_author_editor_source (vxxxxors, xxxxors, args, list_name)
    local function parse_vauthors_veditors (args, vparam, list_name)
    local lastfirst = false;
    local names = {}; -- table of names assembled from |vauthors=, |author-maskn=, |author-linkn=
    if select_one( args, cfg.aliases[list_name .. '-Last'], 'redundant_parameters', 1 ) or -- do this twice incase we have a first 1 without a last1
    local v_name_table = {};
    select_one( args, cfg.aliases[list_name .. '-Last'], 'redundant_parameters', 2 ) then
    local etal = false; -- return value set to true when we find some form of et al. vauthors parameter
    lastfirst=true;
    local last, first, link, mask;
    end
    local corporate = false;
     
     
    if (is_set (vxxxxors) and true == lastfirst) or -- these are the three error conditions
    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)
    (is_set (vxxxxors) and is_set (xxxxors)) or
    if vparam:find ('%[%[') or vparam:find ('%]%]') then -- no wikilinking vauthors names
    (true == lastfirst and is_set (xxxxors)) then
    add_vanc_error ();
    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, { set_error( 'redundant_parameters',
    {err_name .. '-name-list parameters'}, true ) } ); -- add error message
    end
    end
    v_name_table = mw.text.split(vparam, "%s*,%s*") -- names are separated by commas


    if true == lastfirst then return 1 end; -- return a number indicating which author name source to use
    for i, v_name in ipairs(v_name_table) do
    if is_set (vxxxxors) then return 2 end;
    if v_name:match ('^%(%(.+%)%)$') then -- corporate authors are wrapped in doubled parenthese to supress vanc formatting and error detection
    if is_set (xxxxors) then return 3 end;
    first = ''; -- set to empty string for concatenation and because it may have been set for previous author/editor
    return 1; -- no authors so return 1; this allows missing author name test to run in case there is a first without last
    last = v_name:match ('^%(%((.+)%)%)$')
    end
    corporate = true;
     
    elseif string.find(v_name, "%s") then
     
        lastfirstTable = {}
    --[[--------------------------< I S _ V A L I D _ P A R A M E T E R _ V A L U E >------------------------------
        lastfirstTable = mw.text.split(v_name, "%s")
     
        first = table.remove(lastfirstTable); -- removes and returns value of last element in table which should be author intials
    This function is used to validate a parameter's assigned value for those parameters that have only a limited number
        last  = table.concat(lastfirstTable, " ") -- returns a string that is the concatenation of all other names that are not initials
    of allowable values (yes, y, true, no, etc).  When the parameter value has not been assigned a value (missing or empty
        if mw.ustring.match (last, '%a+%s+%u+%s+%a+') or mw.ustring.match (v_name, ' %u %u$') then
    in the source template) the function refurns true. If the parameter value is one of the list of allowed values returns
    add_vanc_error (); -- matches last II last; the case when a comma is missing or a space between two intiials
    true; else, emits an error message and returns false.
    end
     
    else
    ]]
    first = ''; -- set to empty string for concatenation and because it may have been set for previous author/editor
     
    last = v_name; -- last name or single corporate name?  Doesn't support multiword corporate names? do we need this?
    local function is_valid_parameter_value (value, name, possible)
    end
    if not is_set (value) then
    return true; -- an empty parameter is ok
    if is_set (first) and not mw.ustring.match (first, "^%u?%u$") then -- first shall contain one or two upper-case letters, nothing else
    elseif in_array(value:lower(), possible) then
    add_vanc_error ();
    return true;
    end
    else
    -- this from extract_names ()
    table.insert( z.message_tail, { set_error( 'invalid_param_val', {name, value}, true ) } ); -- not an allowed value so add error message
    link = select_one( args, cfg.aliases[list_name .. '-Link'], 'redundant_parameters', i );
    return false
    mask = select_one( args, cfg.aliases[list_name .. '-Mask'], 'redundant_parameters', i );
    names[i] = {last = last, first = first, link = link, mask = mask, corporate=corporate}; -- add this assembled name to our names list
    end
    end
    return names, etal; -- all done, return our list of names
    end
    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 >------------------------


    --[[--------------------------< I S _ P A R A M E T E R _ E X T _ W I K I L I N K >----------------------------
    Select one of |authors=, |authorn= / |lastn / firstn=, or |vauthors= as the source of the author name list or
    select one of |editors=, |editorn= / editor-lastn= / |editor-firstn= or |veditors= as the source of the editor name list.


    Return true if a parameter value has a string that begins and ends with square brackets [ and ] and the first
    Only one of these appropriate three will be used.  The hierarchy is: |authorn= (and aliases) highest and |authors= lowest and
    characters following the opening bracket obey the rules of a uri scheme (see check_url())The test will also find
    similarly, |editorn= (and aliases) highest and |editors= lowest
    external wikilinks that use protocol relative urls.
     
    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 listThere 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 or editors as appropriate.


    ]]
    ]]


    local function is_parameter_ext_wikilink (value)
    local function select_author_editor_source (vxxxxors, xxxxors, args, list_name)
    if value:match ("%[%[%a+:") then -- if a wikilink with namespace (interwiki)
    local lastfirst = false;
    return false;
    if select_one( args, cfg.aliases[list_name .. '-Last'], 'none', 1 ) or -- do this twice incase we have a first 1 without a last1
    elseif value:match ("%[%a[%a%d%+%.%-]*:.*%]") or value:match ("%[//.*%]") then -- does the param value contain an external wikilink?
    select_one( args, cfg.aliases[list_name .. '-Last'], 'none', 2 ) then
    -- elseif value:match ("%[%a[%a%d%+%.%-]*:%S.*%]") or value:match ("%[//.*%]") then -- does the param value contain an external wikilink?
    lastfirst=true;
    return true;
    else
    return false;
    end
    end
    end


    if (is_set (vxxxxors) and true == lastfirst) or -- these are the three error conditions
    (is_set (vxxxxors) and is_set (xxxxors)) or
    (true == lastfirst and 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, { set_error( 'redundant_parameters',
    {err_name .. '-name-list parameters'}, true ) } ); -- add error message
    end


    --[[-------------------------< C H E C K _ F O R _ U R L >-----------------------------------------------------
    if true == lastfirst then return 1 end; -- return a number indicating which author name source to use
    if is_set (vxxxxors) then return 2 end;
    if 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


    loop through a list of parameters and their values.  Look at the value and if it has an external link, emit an error message.


    ]]
    --[[--------------------------< I S _ V A L I D _ P A R A M E T E R _ V A L U E >------------------------------


    local function check_for_url (parameter_list)
    This function is used to validate a parameter's assigned value for those parameters that have only a limited number
    local error_message = '';
    of allowable values (yes, y, true, no, etc).  When the parameter value has not been assigned a value (missing or empty
    for k, v in pairs (parameter_list) do -- for each parameter in the list
    in the source template) the function refurns true.  If the parameter value is one of the list of allowed values returns
    if is_parameter_ext_wikilink (v) then -- look at the value; if there is a url add an error message
    true; else, emits an error message and returns false.
    if 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
    local function is_valid_parameter_value (value, name, possible)
    end
    if not is_set (value) then
    end
    return true; -- an empty parameter is ok
    if is_set (error_message) then -- done looping, if there is an error message, display it
    elseif in_array(value:lower(), possible) then
    table.insert( z.message_tail, { set_error( 'param_has_ext_link', {error_message}, true ) } );
    return true;
    else
    table.insert( z.message_tail, { set_error( 'invalid_param_val', {name, value}, true ) } ); -- not an allowed value so add error message
    return false
    end
    end
    end
    end




    --[[--------------------------< C I T A T I O N 0 >------------------------------------------------------------
    --[[--------------------------< T E R M I N A T E _ N A M E _ L I S T >----------------------------------------


    This is the main function doing the majority of the citation formatting.
    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 citation0( config, args)
    local function terminate_name_list (name_list, sepc)
    --[[
    if (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
    Load Input Parameters
    return name_list .. " "; -- don't add another
    The argument_wrapper facilitates the mapping of multiple aliases to single internal variable.
    else
    ]]
    return name_list .. sepc .. ' '; -- otherwise terninate the name list
    local A = argument_wrapper( args );
    end
    end


    local i
     
    local PPrefix = A['PPrefix']
    --[[-------------------------< F O R M A T _ V O L U M E _ I S S U E >----------------------------------------
    local PPPrefix = A['PPPrefix']
     
    local NoPP = A['NoPP']
    returns the concatenation of the formatted volume and issue parameters as a single string; or formatted volume
    if is_set (NoPP) and is_valid_parameter_value (NoPP, 'nopp', cfg.keywords ['yes_true_y']) then
    or formatted issue, or an empty string if neither are set.
    PPPrefix = ''; -- unset these, prefix if used is in |page= or |pages=
     
    PPrefix = '';
    ]]
    else
    NoPP = nil; -- unset, used as a flag later
    local function format_volume_issue (volume, issue, cite_class, origin, sepc, lower)
    if not is_set (volume) and not is_set (issue) then
    return '';
    end
    if 'magazine' == cite_class or (in_array (cite_class, {'citation', 'map'}) and 'magazine' == origin) then
    if is_set (volume) and is_set (issue) then
    return wrap_msg ('vol-no', {sepc, volume, issue}, lower);
    elseif is_set (volume) then
    return wrap_msg ('vol', {sepc, volume}, lower);
    else
    return wrap_msg ('issue', {sepc, issue}, lower);
    end
    end
    end
    local vol = '';
    -- Pick out the relevant fields from the arguments. Different citation templates
    if is_set (volume) then
    -- define different field names for the same underlying things.
    if (4 < mw.ustring.len(volume)) then
    local author_etal;
    vol = substitute (cfg.messages['j-vol'], {sepc, volume});
    local a = {}; -- authors list from |lastn= / |firstn= pairs or |vauthors=
    else
    local Authors;
    vol = wrap_style ('vol-bold', hyphen_to_dash(volume));
    local NameListFormat = A['NameListFormat'];
     
    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
    NameListFormat = 'vanc'; -- override whatever |name-list-format= 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=
    end
    end
    end
    end
    if is_set (issue) then
    return vol .. substitute (cfg.messages['j-issue'], issue);
    end
    return vol;
    end


    local Coauthors = A['Coauthors'];
    --[[-------------------------< F O R M A T _ P A G E S _ S H E E T S >-----------------------------------------
    local Others = A['Others'];


    local editor_etal;
    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 e = {}; -- editors list from |editor-lastn= / |editor-firstn= pairs or |veditors=
    The return order is:
    local Editors;
    page, pages, sheet, sheets
     
    Singular has priority over plural when both are provided.
     
    ]]


    do -- to limit scope of selected
    local function format_pages_sheets (page, pages, sheet, sheets, cite_class, origin, sepc, nopp, lower)
    local selected = select_author_editor_source (A['Veditors'], A['Editors'], args, 'EditorList');
    if 'map' == cite_class then -- only cite map supports sheet(s) as in-source locators
    if 1 == selected then
    if is_set (sheet) then
    e, editor_etal = extract_names (args, 'EditorList'); -- fetch editor list from |editorn= / |editor-lastn= / |editor-firstn=, |editor-linkn=, and |editor-maskn=
    if 'journal' == origin then
    elseif 2 == selected then
    return '', '', wrap_msg ('j-sheet', sheet, lower), '';
    NameListFormat = 'vanc'; -- override whatever |name-list-format= might be
    else
    e, editor_etal = parse_vauthors_veditors (args, args.veditors, 'EditorList'); -- fetch editor list from |veditors=, |editor-linkn=, and |editor-maskn=
    return '', '', wrap_msg ('sheet', {sepc, sheet}, lower), '';
    elseif 3 == selected then
    end
    Editors = A['Editors']; -- use content of |editors=
    elseif 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
    end
    end


    local t = {}; -- translators list from |translator-lastn= / translator-firstn= pairs
    local is_journal = 'journal' == cite_class or (in_array (cite_class, {'citation', 'map'}) and 'journal' == origin);
    local Translators; -- assembled trnaslators name list
     
    t = extract_names (args, 'TranslatorList'); -- fetch translator list from |translatorn= / |translator-lastn=, -firstn=, -linkn=, -maskn=
    if is_set (page) then
    if is_journal then
    return substitute (cfg.messages['j-page(s)'], page), '', '', '';
    elseif not nopp then
    return substitute (cfg.messages['p-prefix'], {sepc, page}), '', '', '';
    else
    return substitute (cfg.messages['nopp'], {sepc, page}), '', '', '';
    end
    elseif is_set(pages) then
    if is_journal then
    return 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 '', substitute (cfg.messages['p-prefix'], {sepc, pages}), '', '';
    elseif not nopp then
    return '', substitute (cfg.messages['pp-prefix'], {sepc, pages}), '', '';
    else
    return '', substitute (cfg.messages['nopp'], {sepc, pages}), '', '';
    end
    end
    if not is_valid_parameter_value (NameListFormat, 'name-list-format', cfg.keywords['name-list-format']) then -- only accepted value for this parameter is 'vanc'
    return '', '', '', ''; -- return empty strings
    NameListFormat = ''; -- anything else, set to empty string
    end
    end
     
    --[[--------------------------< C I T A T I O N 0 >------------------------------------------------------------
     
    This is the main function doing the majority of the citation formatting.


    local Year = A['Year'];
    ]]
    local PublicationDate = A['PublicationDate'];
    local OrigYear = A['OrigYear'];
    local Date = A['Date'];
    local LayDate = A['LayDate'];
    ------------------------------------------------- Get title data
    local Title = A['Title'];
    local ScriptTitle = A['ScriptTitle'];
    local BookTitle = A['BookTitle'];
    local Conference = A['Conference'];
    local TransTitle = A['TransTitle'];
    local TitleNote = A['TitleNote'];
    local TitleLink = A['TitleLink'];
    local Chapter = A['Chapter'];
    local ScriptChapter = A['ScriptChapter'];
    local ChapterLink -- = A['ChapterLink']; -- deprecated as a parameter but still used internally by cite episode
    local TransChapter = A['TransChapter'];
    local TitleType = A['TitleType'];
    local Degree = A['Degree'];
    local Docket = A['Docket'];
    local ArchiveFormat = A['ArchiveFormat'];
    local ArchiveURL = A['ArchiveURL'];
    local URL = A['URL']
    local URLorigin = A:ORIGIN('URL'); -- get name of parameter that holds URL
    local ChapterURL = A['ChapterURL'];
    local ChapterURLorigin = A:ORIGIN('ChapterURL'); -- get name of parameter that holds ChapterURL
    local ConferenceFormat = A['ConferenceFormat'];
    local ConferenceURL = A['ConferenceURL'];
    local ConferenceURLorigin = A:ORIGIN('ConferenceURL'); -- get name of parameter that holds ConferenceURL
    local Periodical = A['Periodical'];


    local Series = A['Series'];
    local function citation0( config, args)
    local Volume = A['Volume'];
    --[[  
    local Issue = A['Issue'];
    Load Input Parameters
    local Position = '';
    The argument_wrapper facilitates the mapping of multiple aliases to single internal variable.
    local Page = A['Page'];
    ]]
    local Pages = hyphen_to_dash( A['Pages'] );
    local A = argument_wrapper( args );
    local At = A['At'];
    local i


    local Edition = A['Edition'];
    -- Pick out the relevant fields from the arguments.  Different citation templates
    local PublicationPlace = A['PublicationPlace']
    -- define different field names for the same underlying things.
    local Place = A['Place'];
    local author_etal;
    local a = {}; -- authors list from |lastn= / |firstn= pairs or |vauthors=
    local PublisherName = A['PublisherName'];
    local Authors;
    local RegistrationRequired = A['RegistrationRequired'];
    local NameListFormat = A['NameListFormat'];
    if not is_valid_parameter_value (RegistrationRequired, 'registration', cfg.keywords ['yes_true_y']) then
    RegistrationRequired=nil;
    end
    local SubscriptionRequired = A['SubscriptionRequired'];
    if not is_valid_parameter_value (SubscriptionRequired, 'subscription', cfg.keywords ['yes_true_y']) then
    SubscriptionRequired=nil;
    end


    local Via = A['Via'];
    do -- to limit scope of selected
    local AccessDate = A['AccessDate'];
    local selected = select_author_editor_source (A['Vauthors'], A['Authors'], args, 'AuthorList');
    local ArchiveDate = A['ArchiveDate'];
    if 1 == selected then
    local Agency = A['Agency'];
    a, author_etal = extract_names (args, 'AuthorList'); -- fetch author list from |authorn= / |lastn= / |firstn=, |author-linkn=, and |author-maskn=
    local DeadURL = A['DeadURL']
    elseif 2 == selected then
    if not is_valid_parameter_value (DeadURL, 'dead-url', cfg.keywords ['deadurl']) then -- set in config.defaults to 'yes'
    NameListFormat = 'vanc'; -- override whatever |name-list-format= might be
    DeadURL = ''; -- anything else, set to empty string
    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=
    end
    end
    end


    local Language = A['Language'];
    local Coauthors = A['Coauthors'];
    local Format = A['Format'];
    local Others = A['Others'];
    local ChapterFormat = A['ChapterFormat'];
    local DoiBroken = A['DoiBroken'];
    local ID = A['ID'];
    local ASINTLD = A['ASINTLD'];
    local IgnoreISBN = A['IgnoreISBN'];
    if not is_valid_parameter_value (IgnoreISBN, 'ignore-isbn-error', cfg.keywords ['yes_true_y']) then
    IgnoreISBN = nil; -- anything else, set to empty string
    end
    local Embargo = A['Embargo'];
    local Class = A['Class']; -- arxiv class identifier


    local ID_list = extract_ids( args );
    local editor_etal;
    local e = {}; -- editors list from |editor-lastn= / |editor-firstn= pairs or |veditors=
    local Editors;


    local Quote = A['Quote'];
    do -- to limit scope of selected
    local selected = select_author_editor_source (A['Veditors'], A['Editors'], args, 'EditorList');
    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
    NameListFormat = 'vanc'; -- override whatever |name-list-format= might be
    e, editor_etal = parse_vauthors_veditors (args, args.veditors, 'EditorList'); -- fetch editor list from |veditors=, |editor-linkn=, and |editor-maskn=
    elseif 3 == selected then
    Editors = A['Editors']; -- use content of |editors=
    end
    end


    local LayFormat = A['LayFormat'];
    local t = {}; -- translators list from |translator-lastn= / translator-firstn= pairs
    local LayURL = A['LayURL'];
    local Translators; -- assembled translators name list
    local LaySource = A['LaySource'];
    t = extract_names (args, 'TranslatorList'); -- fetch translator list from |translatorn= / |translator-lastn=, -firstn=, -linkn=, -maskn=
    local Transcript = A['Transcript'];
    local TranscriptFormat = A['TranscriptFormat'];
    local c = {}; -- contributors list from |contributor-lastn= / contributor-firstn= pairs
    local TranscriptURL = A['TranscriptURL']  
    local Contributors; -- assembled contributors name list
    local TranscriptURLorigin = A:ORIGIN('TranscriptURL'); -- get name of parameter that holds TranscriptURL
    local Contribution = A['Contribution'];
     
    if in_array(config.CitationClass, {"book","citation"}) and not is_set(A['Periodical']) then -- |contributor= and |contribution= only supported in book cites
    local LastAuthorAmp = A['LastAuthorAmp'];
    c = extract_names (args, 'ContributorList'); -- fetch contributor list from |contributorn= / |contributor-lastn=, -firstn=, -linkn=, -maskn=
    if not is_valid_parameter_value (LastAuthorAmp, 'last-author-amp', cfg.keywords ['yes_true_y']) then
    LastAuthorAmp = nil; -- set to empty string
    if 0 < #c then
    if not is_set (Contribution) then -- |contributor= requires |contribution=
    table.insert( z.message_tail, { set_error( '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, { set_error( 'contributor_missing_required_param', 'author')}); -- add missing author error message
    c = {}; -- blank the contributors' table; it is used as a flag later
    end
    end
    end
    local no_tracking_cats = A['NoTracking'];
    else -- if not a book cite
    if not is_valid_parameter_value (no_tracking_cats, 'no-tracking', cfg.keywords ['yes_true_y']) then
    if select_one (args, cfg.aliases['ContributorList-Last'], 'redundant_parameters', 1 ) then -- are there contributor name list parameters?
    no_tracking_cats = nil; -- set to empty string
    table.insert( z.message_tail, { set_error( 'contributor_ignored')}); -- add contributor ignored error message
    end
    end
     
    Contribution = nil; -- unset
    --these are used by cite interview
    local Callsign = A['Callsign'];
    local City = A['City'];
    local Program = A['Program'];
     
    --local variables that are not cs1 parameters
    local use_lowercase; -- controls capitalization of certain static text
    local this_page = mw.title.getCurrentTitle(); -- also used for COinS and for language
    local anchor_year; -- used in the CITEREF identifier
    local COinS_date; -- used in the COinS metadata
     
    -- set default parameter values defined by |mode= parameter.  If |mode= is empty or omitted, use CitationClass to set these values
    local Mode = A['Mode'];
    if not is_valid_parameter_value (Mode, 'mode', cfg.keywords['mode']) then
    Mode = '';
    end
    end
    local sepc; -- separator between citation elements for CS1 a period, for CS2, a comma
    local PostScript;
    local Ref;
    sepc, PostScript, Ref = set_style (Mode:lower(), A['PostScript'], A['Ref'], config.CitationClass);
    use_lowercase = ( sepc == ',' ); -- used to control capitalization for certain static text


    --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 is_valid_parameter_value (NameListFormat, 'name-list-format', cfg.keywords['name-list-format']) then -- only accepted value for this parameter is 'vanc'
    if not is_set (no_tracking_cats) then -- ignore if we are already not going to categorize this page
    NameListFormat = ''; -- anything else, set to empty string
    if 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
    end


    -- check for extra |page=, |pages= or |at= parameters.
    local Year = A['Year'];
    if is_set(Page) then
    local PublicationDate = A['PublicationDate'];
    if is_set(Pages) or is_set(At) then
    local OrigYear = A['OrigYear'];
    Page = Page .. " " .. set_error('extra_pages'); -- add error message
    local Date = A['Date'];
    Pages = ''; -- unset the others
    local LayDate = A['LayDate'];
    At = '';
    ------------------------------------------------- Get title data
    end
    local Title = A['Title'];
    extra_text_in_page_check (Page, NoPP); -- add this page to maint cat if |page= value begins with what looks like p. or pp.
    local ScriptTitle = A['ScriptTitle'];
    elseif is_set(Pages) then
    local BookTitle = A['BookTitle'];
    if is_set(At) then
    local Conference = A['Conference'];
    Pages = Pages .. " " .. set_error('extra_pages'); -- add error messages
    local TransTitle = A['TransTitle'];
    At = ''; -- unset
    local TitleNote = A['TitleNote'];
    local TitleLink = A['TitleLink'];
    if is_set (TitleLink) and false == link_param_ok (TitleLink) then
    table.insert( z.message_tail, { set_error( 'bad_paramlink', A:ORIGIN('TitleLink'))}); -- url or wikilink in |title-link=;
    end
    end
    extra_text_in_page_check (Pages, NoPP); -- add this page to maint cat if |page= value begins with what looks like p. or pp.
    end


    -- both |publication-place= and |place= (|location=) allowed if different
    local Chapter = A['Chapter'];
    if not is_set(PublicationPlace) and is_set(Place) then
    local ScriptChapter = A['ScriptChapter'];
    PublicationPlace = Place; -- promote |place= (|location=) to |publication-place
    local ChapterLink -- = A['ChapterLink']; -- deprecated as a parameter but still used internally by cite episode
    end
    local TransChapter = A['TransChapter'];
    local TitleType = A['TitleType'];
    if PublicationPlace == Place then Place = ''; end -- don't need both if they are the same
    local Degree = A['Degree'];
    local Docket = A['Docket'];
    --[[
    local ArchiveFormat = A['ArchiveFormat'];
    Parameter remapping for cite encyclopedia:
    local ArchiveURL = A['ArchiveURL'];
    When the citation has these parameters:
    local URL = A['URL']
    |encyclopedia and |title then map |title to |article and |encyclopedia to |title
    local URLorigin = A:ORIGIN('URL'); -- get name of parameter that holds URL
    |encyclopedia and |article then map |encyclopedia to |title
    local ChapterURL = A['ChapterURL'];
    |encyclopedia then map |encyclopedia to |title
    local ChapterURLorigin = A:ORIGIN('ChapterURL'); -- get name of parameter that holds ChapterURL
    local ConferenceFormat = A['ConferenceFormat'];
    local ConferenceURL = A['ConferenceURL'];
    local ConferenceURLorigin = A:ORIGIN('ConferenceURL'); -- get name of parameter that holds ConferenceURL
    local Periodical = A['Periodical'];
    local Periodical_origin = A:ORIGIN('Periodical'); -- get the name of the periodical parameter


    |trans_title maps to |trans_chapter when |title is re-mapped
    local Series = A['Series'];
    |url maps to |chapterurl when |title is remapped
    local Volume;
    local Issue;
    local Page;
    local Pages;
    local At;


    All other combinations of |encyclopedia, |title, and |article are not modified
    if in_array (config.CitationClass, cfg.templates_using_volume) and not ('conference' == config.CitationClass and not is_set (Periodical)) then
    Volume = A['Volume'];
    end
    if in_array (config.CitationClass, cfg.templates_using_issue) and not (in_array (config.CitationClass, {'conference', 'map'}) and not is_set (Periodical))then
    Issue = A['Issue'];
    end
    local Position = '';
    if not 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 = A['PublicationPlace']
    local Place = A['Place'];
    local PublisherName = A['PublisherName'];
    local RegistrationRequired = A['RegistrationRequired'];
    if not is_valid_parameter_value (RegistrationRequired, 'registration', cfg.keywords ['yes_true_y']) then
    RegistrationRequired=nil;
    end
    local SubscriptionRequired = A['SubscriptionRequired'];
    if not is_valid_parameter_value (SubscriptionRequired, 'subscription', cfg.keywords ['yes_true_y']) then
    SubscriptionRequired=nil;
    end


    local Encyclopedia = A['Encyclopedia'];
    local Via = A['Via'];
     
    local AccessDate = A['AccessDate'];
    if ( config.CitationClass == "encyclopaedia" ) or ( config.CitationClass == "citation" and is_set (Encyclopedia)) then -- test code for citation
    local ArchiveDate = A['ArchiveDate'];
    if is_set(Periodical) then -- Periodical is set when |encyclopedia is set
    local Agency = A['Agency'];
    if is_set(Title) or is_set (ScriptTitle) then
    local DeadURL = A['DeadURL']
    if not is_set(Chapter) then
    if not is_valid_parameter_value (DeadURL, 'dead-url', cfg.keywords ['deadurl']) then -- set in config.defaults to 'yes'
    Chapter = Title; -- |encyclopedia and |title are set so map |title to |article and |encyclopedia to |title
    DeadURL = ''; -- anything else, set to empty string
    ScriptChapter = ScriptTitle;
    TransChapter = TransTitle;
    ChapterURL = URL;
    if not is_set (ChapterURL) and is_set (TitleLink) then
    Chapter= '[[' .. TitleLink .. '|' .. Chapter .. ']]';
    end
    Title = Periodical;
    ChapterFormat = Format;
    Periodical = ''; -- redundant so unset
    TransTitle = '';
    URL = '';
    Format = '';
    TitleLink = '';
    ScriptTitle = '';
    end
    else -- |title not set
    Title = Periodical; -- |encyclopedia set and |article set or not set so map |encyclopedia to |title
    Periodical = ''; -- redundant so unset
    end
    end
    end
    end


    -- Special case for cite techreport.
    local Language = A['Language'];
    if (config.CitationClass == "techreport") then -- special case for cite techreport
    local Format = A['Format'];
    if is_set(Issue) then -- cite techreport uses 'number', which other citations aliase to 'issue'
    local ChapterFormat = A['ChapterFormat'];
    if not is_set(ID) then -- can we use ID for the "number"?
    local DoiBroken = A['DoiBroken'];
    ID = Issue; -- yes, use it
    local ID = A['ID'];
    Issue = ""; -- unset Issue so that "number" isn't duplicated in the rendered citation or COinS metadata
    local ASINTLD = A['ASINTLD'];
    else -- can't use ID so emit error message
    local IgnoreISBN = A['IgnoreISBN'];
    ID = ID .. " " .. set_error('redundant_parameters', '<code>&#124;id=</code> and <code>&#124;number=</code>');
    if not is_valid_parameter_value (IgnoreISBN, 'ignore-isbn-error', cfg.keywords ['yes_true_y']) then
    end
    IgnoreISBN = nil; -- anything else, set to empty string
    end
    end
    end
    local Embargo = A['Embargo'];
    local Class = A['Class']; -- arxiv class identifier
     
    local ID_list = extract_ids( args );
     
    local Quote = A['Quote'];
     
    local LayFormat = A['LayFormat'];
    local LayURL = A['LayURL'];
    local LaySource = A['LaySource'];
    local Transcript = A['Transcript'];
    local TranscriptFormat = A['TranscriptFormat'];
    local TranscriptURL = A['TranscriptURL']
    local TranscriptURLorigin = A:ORIGIN('TranscriptURL'); -- get name of parameter that holds TranscriptURL


    -- special case for cite interview
    local LastAuthorAmp = A['LastAuthorAmp'];
    if (config.CitationClass == "interview") then
    if not is_valid_parameter_value (LastAuthorAmp, 'last-author-amp', cfg.keywords ['yes_true_y']) then
    if is_set(Program) then
    LastAuthorAmp = nil; -- set to empty string
    ID = ' ' .. Program;
    end
    end
    if is_set(Callsign) then
    local no_tracking_cats = A['NoTracking'];
    if is_set(ID) then
    if not is_valid_parameter_value (no_tracking_cats, 'no-tracking', cfg.keywords ['yes_true_y']) then
    ID = ID .. sepc .. ' ' .. Callsign;
    no_tracking_cats = nil; -- set to empty string
    else
    ID = ' ' .. Callsign;
    end
    end
    if is_set(City) then
    if is_set(ID) then
    ID = ID .. sepc .. ' ' .. City;
    else
    ID = ' ' .. City;
    end
    end
    end


    if is_set(Others) then
    --these are used by cite interview
    if is_set(TitleType) then
    local Callsign = A['Callsign'];
    Others = ' ' .. TitleType .. ' with ' .. Others;
    local City = A['City'];
    TitleType = '';
    local Program = A['Program'];
    else
     
    Others = ' ' .. 'Interview with ' .. Others;
    --local variables that are not cs1 parameters
    end
    local use_lowercase; -- controls capitalization of certain static text
    else
    local this_page = mw.title.getCurrentTitle(); -- also used for COinS and for language
    Others = '(Interview)';
    local anchor_year; -- used in the CITEREF identifier
    end
    local COinS_date = {}; -- holds date info extracted from |date= for the COinS metadata by Module:Date verification
    end


    -- special case for cite mailing list
    -- set default parameter values defined by |mode= parameter.  If |mode= is empty or omitted, use CitationClass to set these values
    if (config.CitationClass == "mailinglist") then
    local Mode = A['Mode'];
    Periodical = A ['MailingList'];
    if not is_valid_parameter_value (Mode, 'mode', cfg.keywords['mode']) then
    Mode = '';
    end
    end
    local sepc; -- separator between citation elements for CS1 a period, for CS2, a comma
    local PostScript;
    local Ref;
    sepc, PostScript, Ref = set_style (Mode:lower(), A['PostScript'], A['Ref'], config.CitationClass);
    use_lowercase = ( sepc == ',' ); -- used to control capitalization for certain static text


    -- Account for the oddity that is {{cite conference}}, before generation of COinS data.
    --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 'conference' == config.CitationClass then
    if not is_set (no_tracking_cats) then -- ignore if we are already not going to categorize this page
    if is_set(BookTitle) then
    if in_array (this_page.nsText, cfg.uncategorized_namespaces) then
    Chapter = Title;
    no_tracking_cats = "true"; -- set no_tracking_cats
    -- ChapterLink = TitleLink; -- |chapterlink= is deprecated
    end
    ChapterURL = URL;
    for _,v in ipairs (cfg.uncategorized_subpages) do -- cycle through page name patterns
    ChapterURLorigin = URLorigin;
    if this_page.text:match (v) then -- test page name against each pattern
    URLorigin = '';
    no_tracking_cats = "true"; -- set no_tracking_cats
    ChapterFormat = Format;
    break; -- bail out if one is found
    TransChapter = TransTitle;
    end
    Title = BookTitle;
    Format = '';
    -- TitleLink = '';
    TransTitle = '';
    URL = '';
    end
    end
    elseif 'speech' ~= config.CitationClass then
    Conference = ''; -- not cite conference or cite speech so make sure this is empty string
    end
    end


    -- cite map oddities
    -- check for extra |page=, |pages= or |at= parameters. (also sheet and sheets while we're at it)
    local Cartography = "";
    select_one( args, {'page', 'p', 'pp', 'pages', 'at', 'sheet', 'sheets'}, 'redundant_parameters' ); -- this is a dummy call simply to get the error message and category
    local Scale = "";
     
    local Sheet = A['Sheet'] or '';
    local NoPP = A['NoPP']  
    local Sheets = A['Sheets'] or '';
    if is_set (NoPP) and is_valid_parameter_value (NoPP, 'nopp', cfg.keywords ['yes_true_y']) then
    if config.CitationClass == "map" then
    NoPP = true;
    Chapter = A['Map'];
    else
    ChapterURL = A['MapURL'];
    NoPP = nil; -- unset, used as a flag later
    TransChapter = A['TransMap'];
    end
    ChapterURLorigin = A:ORIGIN('MapURL');
     
    ChapterFormat = A['MapFormat'];
    if is_set(Page) then
    if is_set(Pages) or is_set(At) then
    Cartography = A['Cartography'];
    Pages = ''; -- unset the others
    if is_set( Cartography ) then
    At = '';
    Cartography = sepc .. " " .. wrap_msg ('cartography', Cartography, use_lowercase);
    end
    end
    extra_text_in_page_check (Page); -- add this page to maint cat if |page= value begins with what looks like p. or pp.
    Scale = A['Scale'];
    elseif is_set(Pages) then
    if is_set( Scale ) then
    if is_set(At) then
    Scale = sepc .. " " .. Scale;
    At = ''; -- unset
    end
    end
    extra_text_in_page_check (Pages); -- add this page to maint cat if |pages= value begins with what looks like p. or pp.
    end
    -- both |publication-place= and |place= (|location=) allowed if different
    if not is_set(PublicationPlace) and is_set(Place) then
    PublicationPlace = Place; -- promote |place= (|location=) to |publication-place
    end
    end
    if PublicationPlace == Place then Place = ''; end -- don't need both if they are the same
    --[[
    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
    |encyclopedia then map |encyclopedia to |title


    -- Account for the oddities that are {{cite episode}} and {{cite serial}}, before generation of COinS data.
    |trans_title maps to |trans_chapter when |title is re-mapped
    if 'episode' == config.CitationClass or 'serial' == config.CitationClass then
    |url maps to |chapterurl when |title is remapped
    local AirDate = A['AirDate'];
     
    local SeriesLink = A['SeriesLink'];
    All other combinations of |encyclopedia, |title, and |article are not modified
    local Network = A['Network'];
    local Station = A['Station'];
    local s, n = {}, {};


    -- do common parameters first
    ]]
    if is_set(Network) then table.insert(n, Network); end
    if is_set(Station) then table.insert(n, Station); end
    ID = table.concat(n, sepc .. ' ');
    if not is_set (Date) then -- promote airdate or Began/Ended to date
    if is_set (AirDate) then
    Date = AirDate;
    end
    end


    if 'episode' == config.CitationClass then -- handle the oddities that are strictly {{cite episode}}
    local Encyclopedia = A['Encyclopedia'];
    local Season = A['Season'];
    local SeriesNumber = A['SeriesNumber'];


    if is_set (Season) and is_set (SeriesNumber) then -- these are mutually exclusive so if both are set
    if ( config.CitationClass == "encyclopaedia" ) or ( config.CitationClass == "citation" and is_set (Encyclopedia)) then -- test code for citation
    table.insert( z.message_tail, { set_error( 'redundant_parameters', {wrap_style ('parameter', 'season') .. ' and ' .. wrap_style ('parameter', 'seriesno')}, true ) } ); -- add error message
    if is_set(Periodical) then -- Periodical is set when |encyclopedia is set
    SeriesNumber = ''; -- unset; prefer |season= over |seriesno=
    if is_set(Title) or is_set (ScriptTitle) then
    end
    if not is_set(Chapter) then
    -- assemble a table of parts concatenated later into Series
    Chapter = Title; -- |encyclopedia and |title are set so map |title to |article and |encyclopedia to |title
    if is_set(Season) then table.insert(s, wrap_msg ('season', Season, use_lowercase)); end
    ScriptChapter = ScriptTitle;
    if is_set(SeriesNumber) then table.insert(s, wrap_msg ('series', SeriesNumber, use_lowercase)); end
    TransChapter = TransTitle;
    if is_set(Issue) then table.insert(s, wrap_msg ('episode', Issue, use_lowercase)); end
    ChapterURL = URL;
    Issue = ''; -- unset because this is not a unique parameter
    if not is_set (ChapterURL) and is_set (TitleLink) then
    Chapter= '[[' .. TitleLink .. '|' .. Chapter .. ']]';
    Chapter = Title; -- promote title parameters to chapter
    end
    ScriptChapter = ScriptTitle;
    Title = Periodical;
    ChapterLink = TitleLink; -- alias episodelink
    ChapterFormat = Format;
    TransChapter = TransTitle;
    Periodical = ''; -- redundant so unset
    ChapterURL = URL;
    TransTitle = '';
    ChapterURLorigin = A:ORIGIN('URL');
    URL = '';
    Format = '';
    Title = Series; -- promote series to title
    TitleLink = '';
    TitleLink = SeriesLink;
    ScriptTitle = '';
    Series = table.concat(s, sepc .. ' '); -- this is concatenation of season, seriesno, episode number
    end
    else -- |title not set
    Title = Periodical; -- |encyclopedia set and |article set or not set so map |encyclopedia to |title
    Periodical = ''; -- redundant so unset
    end
    end
    end


    if is_set (ChapterLink) and not is_set (ChapterURL) then -- link but not URL
    -- Special case for cite techreport.
    Chapter = '[[' .. ChapterLink .. '|' .. Chapter .. ']]'; -- ok to wikilink
    if (config.CitationClass == "techreport") then -- special case for cite techreport
    elseif is_set (ChapterLink) and is_set (ChapterURL) then -- if both are set, URL links episode;
    if is_set(A['Number']) then -- cite techreport uses 'number', which other citations alias to 'issue'
    Series = '[[' .. ChapterLink .. '|' .. Series .. ']]'; -- series links with ChapterLink (episodelink -> TitleLink -> ChapterLink) ugly
    if not 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
    -- ID = ID .. " " .. set_error('redundant_parameters', '<code>&#124;id=</code> and <code>&#124;number=</code>');
    table.insert( z.message_tail, { set_error('redundant_parameters', {wrap_style ('parameter', 'id') .. ' and ' .. wrap_style ('parameter', 'number')}, true )});
    end
    end
    URL = ''; -- unset
    end
    TransTitle = '';
    end
    ScriptTitle = '';
     
    -- special case for cite interview
    else -- now oddities that are cite serial
    if (config.CitationClass == "interview") then
    Issue = ''; -- unset because this parameter no longer supported by the citation/core version of cite serial
    if is_set(Program) then
    Chapter = A['Episode']; -- TODO: make |episode= available to cite episode someday?
    ID = ' ' .. Program;
    if is_set (Series) and is_set (SeriesLink) then
    end
    Series = '[[' .. SeriesLink .. '|' .. Series .. ']]';
    if is_set(Callsign) then
    if is_set(ID) then
    ID = ID .. sepc .. ' ' .. Callsign;
    else
    ID = ' ' .. Callsign;
    end
    end
    if is_set(City) then
    if is_set(ID) then
    ID = ID .. sepc .. ' ' .. City;
    else
    ID = ' ' .. City;
    end
    end
    Series = wrap_style ('italic-title', Series); -- series is italicized
    end
    end
    end
    -- end of {{cite episode}} stuff


    -- Account for the oddities that are {{cite arxiv}}, before generation of COinS data.
    if is_set(Others) then
    if 'arxiv' == config.CitationClass then
    if is_set(TitleType) then
    if not is_set (ID_list['ARXIV']) then -- |arxiv= or |eprint= required for cite arxiv
    Others = ' ' .. TitleType .. ' with ' .. Others;
    table.insert( z.message_tail, { set_error( 'arxiv_missing', {}, true ) } ); -- add error message
    TitleType = '';
    elseif is_set (Series) then -- series is an alias of version
    else
    ID_list['ARXIV'] = ID_list['ARXIV'] .. Series; -- concatenate version onto the end of the arxiv identifier
    Others = ' ' .. 'Interview with ' .. Others;
    Series = ''; -- unset
    end
    deprecated_parameter ('version'); -- deprecated parameter but only for cite arxiv
    else
    end
    Others = '(Interview)';
    if first_set (AccessDate, At, Chapter, Format, Page, Pages, Periodical, PublisherName, URL, -- a crude list of parameters that are not supported by cite arxiv
    ID_list['ASIN'], ID_list['BIBCODE'], ID_list['DOI'], ID_list['ISBN'], ID_list['ISSN'],
    ID_list['JFM'], ID_list['JSTOR'], ID_list['LCCN'], ID_list['MR'], ID_list['OCLC'], ID_list['OL'],
    ID_list['OSTI'], ID_list['PMC'], ID_list['PMID'], ID_list['RFC'], ID_list['SSRN'], ID_list['USENETID'], ID_list['ZBL']) then
    table.insert( z.message_tail, { set_error( 'arxiv_params_not_supported', {}, true ) } ); -- add error message
     
    AccessDate= ''; -- set these to empty string; not supported in cite arXiv
    PublisherName = ''; -- (if the article has been published, use cite journal, or other)
    Chapter = '';
    URL = '';
    Format = '';
    Page = ''; Pages = ''; At = '';
    end
    end
    Periodical = 'arXiv'; -- set to arXiv for COinS; after that, must be set to empty string
    end
    end


    -- handle type parameter for those CS1 citations that have default values
    -- special case for cite mailing list
     
    if (config.CitationClass == "mailinglist") then
    if in_array(config.CitationClass, {"AV-media-notes", "DVD-notes", "mailinglist", "map", "podcast", "pressrelease", "report", "techreport", "thesis"}) then
    Periodical = A ['MailingList'];
    TitleType = set_titletype (config.CitationClass, TitleType);
    elseif 'mailinglist' == A:ORIGIN('Periodical') then
    if is_set(Degree) and "Thesis" == TitleType then -- special case for cite thesis
    Periodical = ''; -- unset because mailing list is only used for cite mailing list
    TitleType = Degree .. " thesis";
    end
    end
    end


    if is_set(TitleType) then -- if type parameter is specified
    -- Account for the oddity that is {{cite conference}}, before generation of COinS data.
    TitleType = " (" .. TitleType .. ")"; -- display it in parentheses
    if 'conference' == config.CitationClass then
    end
    if is_set(BookTitle) then
     
    Chapter = Title;
    -- legacy: promote concatenation of |month=, and |year= to Date if Date not set; or, promote PublicationDate to Date if neither Date nor Year are set.
    -- ChapterLink = TitleLink; -- |chapterlink= is deprecated
    if not is_set (Date) then
    ChapterURL = URL;
    Date = Year; -- promote Year to Date
    ChapterURLorigin = URLorigin;
    Year = nil; -- make nil so Year as empty string isn't used for CITEREF
    URLorigin = '';
    if not is_set (Date) and is_set(PublicationDate) then -- use PublicationDate when |date= and |year= are not set
    ChapterFormat = Format;
    Date = PublicationDate; -- promote PublicationDate to Date
    TransChapter = TransTitle;
    PublicationDate = ''; -- unset, no longer needed
    Title = BookTitle;
    Format = '';
    -- TitleLink = '';
    TransTitle = '';
    URL = '';
    end
    end
    elseif 'speech' ~= config.CitationClass then
    Conference = ''; -- not cite conference or cite speech so make sure this is empty string
    end
    end


    if PublicationDate == Date then PublicationDate = ''; end -- if PublicationDate is same as Date, don't display in rendered citation
    -- cite map oddities
     
    local Cartography = "";
    --[[
    local Scale = "";
    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
    local Sheet = A['Sheet'] or '';
    we get the date used in the metadata.
    local Sheets = A['Sheets'] or '';
     
    if config.CitationClass == "map" then
    Date validation supporting code is in Module:Citation/CS1/Date_validation
    Chapter = A['Map'];
    ]]
    ChapterURL = A['MapURL'];
    do -- create defined block to contain local variables error_message and mismatch
    TransChapter = A['TransMap'];
    local error_message = '';
    ChapterURLorigin = A:ORIGIN('MapURL');
    -- AirDate has been promoted to Date so not necessary to check it
    ChapterFormat = A['MapFormat'];
    anchor_year, COinS_date, error_message = dates({['access-date']=AccessDate, ['archive-date']=ArchiveDate, ['date']=Date, ['doi-broken-date']=DoiBroken,
    ['embargo']=Embargo, ['lay-date']=LayDate, ['publication-date']=PublicationDate, ['year']=Year});
    Cartography = A['Cartography'];
    if is_set( Cartography ) then
    Cartography = sepc .. " " .. wrap_msg ('cartography', Cartography, use_lowercase);
    end
    Scale = A['Scale'];
    if is_set( Scale ) then
    Scale = sepc .. " " .. Scale;
    end
    end


    if is_set (Year) and is_set (Date) then -- both |date= and |year= not normally needed;
    -- Account for the oddities that are {{cite episode}} and {{cite serial}}, before generation of COinS data.
    local mismatch = year_date_check (Year, Date)
    if 'episode' == config.CitationClass or 'serial' == config.CitationClass then
    if 0 == mismatch then -- |year= does not match a year-value in |date=
    local AirDate = A['AirDate'];
    if is_set (error_message) then -- if there is already an error message
    local SeriesLink = A['SeriesLink'];
    error_message = error_message .. ', '; -- tack on this additional message
    if is_set (SeriesLink) and false == link_param_ok (SeriesLink) then
    end
    table.insert( z.message_tail, { set_error( 'bad_paramlink', A:ORIGIN('SeriesLink'))});
    error_message = error_message .. '&#124;year= / &#124;date= mismatch';
    elseif 1 == mismatch then -- |year= matches year-value in |date=
    add_maint_cat ('date_year');
    end
    end
    local Network = A['Network'];
    local Station = A['Station'];
    local s, n = {}, {};
    -- do common parameters first
    if is_set(Network) then table.insert(n, Network); end
    if is_set(Station) then table.insert(n, Station); end
    ID = table.concat(n, sepc .. ' ');
    if not is_set (Date) and is_set (AirDate) then -- promote airdate to date
    Date = AirDate;
    end
    end


    if is_set(error_message) then
    if 'episode' == config.CitationClass then -- handle the oddities that are strictly {{cite episode}}
    table.insert( z.message_tail, { set_error( 'bad_date', {error_message}, true ) } ); -- add this error message
    local Season = A['Season'];
    end
    local SeriesNumber = A['SeriesNumber'];
    end -- end of do


    -- Account for the oddity that is {{cite journal}} with |pmc= set and |url= not set.  Do this after date check but before COInS.
    if is_set (Season) and is_set (SeriesNumber) then -- these are mutually exclusive so if both are set
    -- Here we unset Embargo if PMC not embargoed (|embargo= not set in the citation) or if the embargo time has expired. Otherwise, holds embargo date
    table.insert( z.message_tail, { set_error( 'redundant_parameters', {wrap_style ('parameter', 'season') .. ' and ' .. wrap_style ('parameter', 'seriesno')}, true ) } ); -- add error message
    Embargo = is_embargoed (Embargo); --
    SeriesNumber = ''; -- unset; prefer |season= over |seriesno=
     
    if config.CitationClass == "journal" and not is_set(URL) and is_set(ID_list['PMC']) then
    if not is_set (Embargo) then -- if not embargoed or embargo has expired
    URL=cfg.id_handlers['PMC'].prefix .. ID_list['PMC']; -- set url to be the same as the PMC external link if not embargoed
    URLorigin = cfg.id_handlers['PMC'].parameters[1]; -- set URLorigin to parameter name for use in error message if citation is missing a |title=
    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 is_set(Title) and
    not is_set(TransTitle) and
    not is_set(ScriptTitle) then
    if 'episode' == config.CitationClass then -- special case for cite episode; is there a better way to do this?
    table.insert( z.message_tail, { set_error( 'citation_missing_title', {'series'}, true ) } );
    else
    table.insert( z.message_tail, { set_error( 'citation_missing_title', {'title'}, true ) } );
    end
    end
    end
    -- assemble a table of parts concatenated later into Series
    if is_set(Season) then table.insert(s, wrap_msg ('season', Season, use_lowercase)); end
    if is_set(SeriesNumber) then table.insert(s, wrap_msg ('series', SeriesNumber, use_lowercase)); end
    if is_set(Issue) then table.insert(s, wrap_msg ('episode', Issue, use_lowercase)); end
    Issue = ''; -- unset because this is not a unique parameter
    if 'none' == Title and is_set(Periodical) and not (( config.CitationClass == "encyclopaedia" ) or ( config.CitationClass == "citation" and is_set (Encyclopedia))) then -- special case
    Chapter = Title; -- promote title parameters to chapter
    Title = ''; -- set title to empty string
    ScriptChapter = ScriptTitle;
    add_maint_cat ('untitled');
    ChapterLink = TitleLink; -- alias episodelink
    end
    TransChapter = TransTitle;
    ChapterURL = URL;
    ChapterURLorigin = A:ORIGIN('URL');
    Title = Series; -- promote series to title
    TitleLink = SeriesLink;
    Series = table.concat(s, sepc .. ' '); -- this is concatenation of season, seriesno, episode number


    check_for_url ({['title']=Title, ['chapter']=Chapter, ['work']=Periodical}); -- adds error message when any of these parameters contain a URL
    if is_set (ChapterLink) and not is_set (ChapterURL) then -- link but not URL
    Chapter = '[[' .. ChapterLink .. '|' .. Chapter .. ']]'; -- ok to wikilink
    elseif is_set (ChapterLink) and is_set (ChapterURL) then -- if both are set, URL links episode;
    Series = '[[' .. ChapterLink .. '|' .. Series .. ']]'; -- series links with ChapterLink (episodelink -> TitleLink -> ChapterLink) ugly
    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 is_set (Series) and is_set (SeriesLink) then
    Series = '[[' .. SeriesLink .. '|' .. Series .. ']]';
    end
    Series = wrap_style ('italic-title', Series); -- series is italicized
    end
    end
    -- end of {{cite episode}} stuff


    -- COinS metadata (see <http://ocoins.info/>) for automated parsing of citation information.
    -- Account for the oddities that are {{cite arxiv}}, before generation of COinS data.
    -- handle the oddity that is cite encyclopedia and {{citation |encyclopedia=something}}. Here we presume that
    if 'arxiv' == config.CitationClass then
    -- when Periodical, Title, and Chapter are all set, then Periodical is the book (encyclopedia) title, Title
    if not is_set (ID_list['ARXIV']) then -- |arxiv= or |eprint= required for cite arxiv
    -- is the article title, and Chapter is a section within the article. So, we remap
    table.insert( z.message_tail, { set_error( 'arxiv_missing', {}, true ) } ); -- add error message
    elseif is_set (Series) then -- series is an alias of version
    local coins_chapter = Chapter; -- default assuming that remapping not required
    ID_list['ARXIV'] = ID_list['ARXIV'] .. Series; -- concatenate version onto the end of the arxiv identifier
    local coins_title = Title; -- et tu
    Series = ''; -- unset
    if 'encyclopaedia' == config.CitationClass or ('citation' == config.CitationClass and is_set (Encyclopedia)) then
    deprecated_parameter ('version'); -- deprecated parameter but only for cite arxiv
    if is_set (Chapter) and is_set (Title) and is_set (Periodical) then -- if all are used then
    coins_chapter = Title; -- remap
    coins_title = Periodical;
    end
    end
    end
    if first_set ({AccessDate, At, Chapter, Format, Page, Pages, Periodical, PublisherName, URL, -- a crude list of parameters that are not supported by cite arxiv
    -- this is the function call to COinS()
    ID_list['ASIN'], ID_list['BIBCODE'], ID_list['DOI'], ID_list['ISBN'], ID_list['ISSN'],
    local OCinSoutput = COinS({
    ID_list['JFM'], ID_list['JSTOR'], ID_list['LCCN'], ID_list['MR'], ID_list['OCLC'], ID_list['OL'],
    ['Periodical'] = Periodical,
    ID_list['OSTI'], ID_list['PMC'], ID_list['PMID'], ID_list['RFC'], ID_list['SSRN'], ID_list['USENETID'], ID_list['ZBL']},27) then
    ['Chapter'] = make_coins_title (coins_chapter, ScriptChapter), -- Chapter and ScriptChapter stripped of bold / italic wikimarkup
    table.insert( z.message_tail, { set_error( 'arxiv_params_not_supported', {}, true ) } ); -- add error message
    ['Title'] = make_coins_title (coins_title, ScriptTitle), -- Title and ScriptTitle stripped of bold / italic wikimarkup
    ['PublicationPlace'] = PublicationPlace,
    ['Date'] = first_set(COinS_date, Date), -- COinS_date has correctly formatted date if Date is valid; any reason to keep Date here?  Should we be including invalid dates in metadata?
    ['Series'] = Series,
    ['Volume'] = Volume,
    ['Issue'] = Issue,
    ['Pages'] = get_coins_pages (first_set(Sheet, Sheets, Page, Pages, At)), -- pages stripped of external links
    ['Edition'] = Edition,
    ['PublisherName'] = PublisherName,
    ['URL'] = first_set( URL, ChapterURL ),
    ['Authors'] = a,
    ['ID_list'] = ID_list,
    ['RawPage'] = this_page.prefixedText,
    }, config.CitationClass);


    -- Account for the oddities that are {{cite arxiv}}, AFTER generation of COinS data.
    AccessDate= ''; -- set these to empty string; not supported in cite arXiv
    if 'arxiv' == config.CitationClass then -- we have set rft.jtitle in COinS to arXiv, now unset so it isn't displayed
    PublisherName = ''; -- (if the article has been published, use cite journal, or other)
    Periodical = ''; -- periodical not allowed in cite arxiv; if article has been published, use cite journal
    Chapter = '';
    URL = '';
    Format = '';
    Page = ''; Pages = ''; At = '';
    end
    Periodical = 'arXiv'; -- set to arXiv for COinS; after that, must be set to empty string
    end
    end


    -- special case for cite newsgroup.  Do this after COinS because we are modifying Publishername to include some static text
    -- handle type parameter for those CS1 citations that have default values
    if 'newsgroup' == config.CitationClass then
    if in_array(config.CitationClass, {"AV-media-notes", "DVD-notes", "mailinglist", "map", "podcast", "pressrelease", "report", "techreport", "thesis"}) then
    if is_set (PublisherName) then
    TitleType = set_titletype (config.CitationClass, TitleType);
    PublisherName = '[[Usenet newsgroup|Newsgroup]]:&nbsp;' .. external_link( 'news:' .. PublisherName, PublisherName );
    if is_set(Degree) and "Thesis" == TitleType then -- special case for cite thesis
    TitleType = Degree .. " thesis";
    end
    end
    end
    end


    if is_set(TitleType) then -- if type parameter is specified
    TitleType = substitute( cfg.messages['type'], TitleType); -- display it in parentheses
    end
    -- legacy: promote concatenation of |month=, and |year= to Date if Date not set; or, promote PublicationDate to Date if neither Date nor Year are set.
    if not 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 is_set (Date) and is_set(PublicationDate) then -- use PublicationDate when |date= and |year= are not set
    Date = PublicationDate; -- promote PublicationDate to Date
    PublicationDate = ''; -- unset, no longer needed
    end
    end


    if PublicationDate == Date then PublicationDate = ''; end -- if PublicationDate is same as Date, don't display in rendered citation


    -- Now perform various field substitutions.
    --[[
    -- We also add leading spaces and surrounding markup and punctuation to the
    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
    -- various parts of the citation, but only when they are non-nil.
    we get the date used in the metadata.
    local EditorCount; -- used only for choosing {ed.) or (eds.) annotation at end of editor name-list
    do
    local last_first_list;
    local maximum;
    local control = {
    format = NameListFormat, -- empty string or 'vanc'
    maximum = nil, -- as if display-authors or display-editors not set
    lastauthoramp = LastAuthorAmp,
    page_name = this_page.text -- get current page name so that we don't wikilink to it via editorlinkn
    };


    do -- do editor name list first because coauthors can modify control table
    Date validation supporting code is in Module:Citation/CS1/Date_validation
    maximum , editor_etal = get_display_authors_editors (A['DisplayEditors'], #e, 'editors', editor_etal);
    ]]
    -- Preserve old-style implicit et al.
    do -- create defined block to contain local variables error_message and mismatch
    if not is_set(maximum) and #e == 4 then
    local error_message = '';
    maximum = 3;
    -- AirDate has been promoted to Date so not necessary to check it
    table.insert( z.message_tail, { set_error('implict_etal_editor', {}, true) } );
    anchor_year, error_message = dates({['access-date']=AccessDate, ['archive-date']=ArchiveDate, ['date']=Date, ['doi-broken-date']=DoiBroken,
    end
    ['embargo']=Embargo, ['lay-date']=LayDate, ['publication-date']=PublicationDate, ['year']=Year}, COinS_date);


    control.maximum = maximum;
    if is_set (Year) and is_set (Date) then -- both |date= and |year= not normally needed;  
    local mismatch = year_date_check (Year, Date)
    last_first_list, EditorCount = list_people(control, e, editor_etal);
    if 0 == mismatch then -- |year= does not match a year-value in |date=
     
    if is_set (error_message) then -- if there is already an error message
    if is_set (Editors) then
    error_message = error_message .. ', '; -- tack on this additional message
    if editor_etal then
    Editors = Editors .. ' ' .. cfg.messages['et al']; -- add et al. to editors parameter beause |display-editors=etal
    EditorCount = 2; -- with et al., |editors= is multiple names; spoof to display (eds.) annotation
    else
    EditorCount = 2; -- we don't know but assume |editors= is multiple names; spoof to display (eds.) annotation
    end
    end
    else
    error_message = error_message .. '&#124;year= / &#124;date= mismatch';
    Editors = last_first_list; -- either an author name list or an empty string
    elseif 1 == mismatch then -- |year= matches year-value in |date=
    add_maint_cat ('date_year');
    end
    end
    end


    if 1 == EditorCount and (true == editor_etal or 1 < #e) then -- only one editor displayed but includes etal then  
    if is_set(error_message) then
    EditorCount = 2; -- spoof to display (eds.) annotation
    table.insert( z.message_tail, { set_error( 'bad_date', {error_message}, true ) } ); -- add this error message
    end
    end
    end
    do -- now do translators
    end -- end of do
    control.maximum = #t; -- number of translators
    Translators = list_people(control, t, false); -- et al not currently supported
    end
    do -- now do authors
    control.maximum , author_etal = get_display_authors_editors (A['DisplayAuthors'], #a, 'authors', author_etal);


    if is_set(Coauthors) then -- if the coauthor field is also used, prevent ampersand and et al. formatting.
    -- Account for the oddity that is {{cite journal}} with |pmc= set and |url= not set. Do this after date check but before COInS.
    control.lastauthoramp = nil;
    -- Here we unset Embargo if PMC not embargoed (|embargo= not set in the citation) or if the embargo time has expired. Otherwise, holds embargo date
    control.maximum = #a + 1;
    Embargo = is_embargoed (Embargo); --
    end
    last_first_list = list_people(control, a, author_etal);


    if is_set (Authors) then
    if config.CitationClass == "journal" and not is_set(URL) and is_set(ID_list['PMC']) then
    Authors, author_etal = name_has_etal (Authors, author_etal, false); -- find and remove variations on et al.
    if not is_set (Embargo) then -- if not embargoed or embargo has expired
    if author_etal then
    URL=cfg.id_handlers['PMC'].prefix .. ID_list['PMC']; -- set url to be the same as the PMC external link if not embargoed
    Authors = Authors .. ' ' .. cfg.messages['et al']; -- add et al. to authors parameter
    URLorigin = cfg.id_handlers['PMC'].parameters[1]; -- set URLorigin to parameter name for use in error message if citation is missing a |title=
    end
    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 is_set(Title) and
    not is_set(TransTitle) and
    not is_set(ScriptTitle) then
    if 'episode' == config.CitationClass then -- special case for cite episode; TODO: is there a better way to do this?
    table.insert( z.message_tail, { set_error( 'citation_missing_title', {'series'}, true ) } );
    else
    else
    Authors = last_first_list; -- either an author name list or an empty string
    table.insert( z.message_tail, { set_error( 'citation_missing_title', {'title'}, true ) } );
    end
    end
    end
    if 'none' == Title and in_array (config.CitationClass, {'journal', 'citation'}) and is_set (Periodical) and 'journal' == A:ORIGIN('Periodical') then -- special case for journal cites
    Title = ''; -- set title to empty string
    add_maint_cat ('untitled');
    end


    end -- end of do
    check_for_url ({ -- add error message when any of these parameters contains a URL
    ['title']=Title,
    [A:ORIGIN('Chapter')]=Chapter,
    [A:ORIGIN('Periodical')]=Periodical,
    [A:ORIGIN('PublisherName')] = PublisherName,
    });


    if not is_set(Authors) and is_set(Coauthors) then -- coauthors aren't displayed if one of authors=, authorn=, or lastn= isn't specified
    -- COinS metadata (see <http://ocoins.info/>) for automated parsing of citation information.
    table.insert( z.message_tail, { set_error('coauthors_missing_author', {}, true) } ); -- emit error message
    -- 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 is_set (Encyclopedia)) then
    if is_set (Chapter) and is_set (Title) and is_set (Periodical) then -- if all are used then
    coins_chapter = Title; -- remap
    coins_title = Periodical;
    end
    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
    end


    -- this is the function call to COinS()
    local OCinSoutput = COinS({
    ['Periodical'] = Periodical,
    ['Encyclopedia'] = Encyclopedia,
    ['Chapter'] = make_coins_title (coins_chapter, ScriptChapter), -- Chapter and ScriptChapter stripped of bold / italic wikimarkup
    ['Map'] = Map,
    ['Degree'] = Degree; -- cite thesis only
    ['Title'] = make_coins_title (coins_title, ScriptTitle), -- Title and ScriptTitle stripped of bold / italic wikimarkup
    ['PublicationPlace'] = PublicationPlace,
    ['Date'] = COinS_date.rftdate, -- COinS_date has correctly formatted date if Date is valid;
    ['Season'] = COinS_date.rftssn,
    ['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'] = get_coins_pages (first_set ({Sheet, Sheets, Page, Pages, At}, 5)), -- pages stripped of external links
    ['Edition'] = Edition,
    ['PublisherName'] = PublisherName,
    ['URL'] = first_set ({ChapterURL, URL}, 2),
    ['Authors'] = coins_author,
    ['ID_list'] = ID_list,
    ['RawPage'] = this_page.prefixedText,
    }, config.CitationClass);


    -- Account for the oddities that are {{cite arxiv}}, AFTER generation of COinS data.
    if 'arxiv' == config.CitationClass then -- we have set rft.jtitle in COinS to arXiv, now unset so it isn't displayed
    Periodical = ''; -- periodical not allowed in cite arxiv; 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
    do -- do-block to limit scope of last_first_list
    if 'newsgroup' == config.CitationClass then
    local last_first_list;
    if is_set (PublisherName) then
    local maximum = A['DisplayAuthors'];
    PublisherName = substitute (cfg.messages['newsgroup'], external_link( 'news:' .. PublisherName, PublisherName, A:ORIGIN('PublisherName') ));
     
    maximum , author_etal = get_display_authors_editors (maximum, #a, 'authors', author_etal);
     
    local control = {
    format = NameListFormat, -- empty string or 'vanc'
    maximum = maximum,
    lastauthoramp = LastAuthorAmp,
    page_name = this_page.text -- get current page name so that we don't wikilink to it via authorlinkn
    };
    if is_set(Coauthors) then -- if the coauthor field is also used, prevent ampersand and et al. formatting.
    control.lastauthoramp = nil;
    control.maximum = #a + 1;
    end
    end
    end
    last_first_list = list_people(control, a, author_etal);


    if is_set (Authors) then
    Authors, author_etal = name_has_etal (Authors, author_etal, false); -- 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 not is_set(Authors) and is_set(Coauthors) then -- coauthors aren't displayed if one of authors=, authorn=, or lastn= isn't specified
    table.insert( z.message_tail, { set_error('coauthors_missing_author', {}, true) } ); -- emit error message
    end


    -- 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.
    local EditorCount; -- used only for choosing {ed.) or (eds.) annotation at end of editor name-list
    local EditorCount; -- used only for choosing {ed.) or (eds.) annotation at end of editor name-list
    do
    do
    local last_first_list;
    local last_first_list;
    local maximum = A['DisplayEditors'];
    local maximum;
     
    maximum , editor_etal = get_display_authors_editors (maximum, #e, 'editors', editor_etal);
    -- Preserve old-style implicit et al.
    if not is_set(maximum) and #e == 4 then
    maximum = 3;
    table.insert( z.message_tail, { set_error('implict_etal_editor', {}, true) } );
    end
     
    local control = {  
    local control = {  
    format = NameListFormat, -- empty string or 'vanc'
    format = NameListFormat, -- empty string or 'vanc'
    maximum = maximum,
    maximum = nil, -- as if display-authors or display-editors not set
    lastauthoramp = LastAuthorAmp,
    lastauthoramp = LastAuthorAmp,
    page_name = this_page.text -- get current page name so that we don't wikilink to it via editorlinkn
    page_name = this_page.text -- get current page name so that we don't wikilink to it via editorlinkn
    };
    };


    last_first_list, EditorCount = list_people(control, e, editor_etal);
    do -- do editor name list first because coauthors can modify control table
    maximum , editor_etal = get_display_authors_editors (A['DisplayEditors'], #e, 'editors', editor_etal);
    -- Preserve old-style implicit et al.
    if not is_set(maximum) and #e == 4 then
    maximum = 3;
    table.insert( z.message_tail, { set_error('implict_etal_editor', {}, true) } );
    end


    if is_set (Editors) then
    control.maximum = maximum;
    if editor_etal then
    Editors = Editors .. ' ' .. cfg.messages['et al']; -- add et al. to editors parameter beause |display-editors=etal
    last_first_list, EditorCount = list_people(control, e, editor_etal, 'editor');
    EditorCount = 2; -- with et al., |editors= is multiple names; spoof to display (eds.) annotation
     
    if is_set (Editors) then
    if editor_etal then
    Editors = Editors .. ' ' .. cfg.messages['et al']; -- add et al. to editors parameter beause |display-editors=etal
    EditorCount = 2; -- with et al., |editors= is multiple names; spoof to display (eds.) annotation
    else
    EditorCount = 2; -- we don't know but assume |editors= is multiple names; spoof to display (eds.) annotation
    end
    else
    else
    EditorCount = 2; -- we don't know but assume |editors= is multiple names; spoof to display (eds.) annotation
    Editors = last_first_list; -- either an author name list or an empty string
    end
     
    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
    else
    Editors = last_first_list; -- either an author name list or an empty string
    end
    end
    do -- now do translators
    control.maximum = #t; -- number of translators
    Translators = list_people(control, t, false, 'translator'); -- et al not currently supported
    end
    do -- now do contributors
    control.maximum = #c; -- number of contributors
    Contributors = list_people(control, c, false, 'contributor'); -- et al not currently supported
    end
    do -- now do authors
    control.maximum , author_etal = get_display_authors_editors (A['DisplayAuthors'], #a, 'authors', author_etal);


    if 1 == EditorCount and (true == editor_etal or 1 < #e) then -- only one editor displayed but includes etal then
    if is_set(Coauthors) then -- if the coauthor field is also used, prevent ampersand and et al. formatting.
    EditorCount = 2; -- spoof to display (eds.) annotation
    control.lastauthoramp = nil;
    control.maximum = #a + 1;
    end
    last_first_list = list_people(control, a, author_etal, 'author');
     
    if is_set (Authors) then
    Authors, author_etal = name_has_etal (Authors, author_etal, false); -- 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 not is_set(Authors) and is_set(Coauthors) then -- coauthors aren't displayed if one of authors=, authorn=, or lastn= isn't specified
    table.insert( z.message_tail, { set_error('coauthors_missing_author', {}, true) } ); -- emit error message
    end
    end
    end
    end
    ]]


    -- apply |[xx-]format= styling; at the end, these parameters hold correctly styled format annotation,
    -- apply |[xx-]format= styling; at the end, these parameters hold correctly styled format annotation,
    -- an error message if the associated url is not set, or an empty string for concatenation
    -- an error message if the associated url is not set, or an empty string for concatenation
    ArchiveFormat = style_format (ArchiveFormat, ArchiveURL, 'archive-format', 'archive-url');
    ArchiveFormat = style_format (ArchiveFormat, ArchiveURL, 'archive-format', 'archive-url');
    ChapterFormat = style_format (ChapterFormat, ChapterURL, 'chapter-format', 'chapter-url');
    ConferenceFormat = style_format (ConferenceFormat, ConferenceURL, 'conference-format', 'conference-url');
    ConferenceFormat = style_format (ConferenceFormat, ConferenceURL, 'conference-format', 'conference-url');
    Format = style_format (Format, URL, 'format', 'url');
    Format = style_format (Format, URL, 'format', 'url');
    LayFormat = style_format (LayFormat, LayURL, 'lay-format', 'lay-url');
    LayFormat = style_format (LayFormat, LayURL, 'lay-format', 'lay-url');
    TranscriptFormat = style_format (TranscriptFormat, TranscriptURL, 'transcript-format', 'transcripturl');
    TranscriptFormat = style_format (TranscriptFormat, TranscriptURL, 'transcript-format', 'transcripturl');
    -- special case for chapter format so no error message or cat when chapter not supported
    if not (in_array(config.CitationClass, {'web','news','journal', 'magazine', 'pressrelease','podcast', 'newsgroup', 'arxiv'}) or
    ('citation' == config.CitationClass and is_set (Periodical) and not is_set (Encyclopedia))) then
    ChapterFormat = style_format (ChapterFormat, ChapterURL, 'chapter-format', 'chapter-url');
    end


    if  not is_set(URL) then --and
    if  not is_set(URL) then --and
    -- not is_set(ArchiveURL) then --and -- prevents format_missing_url error from registering
    if in_array(config.CitationClass, {"web","podcast", "mailinglist"}) then -- Test if cite web or cite podcast |url= is missing or empty
    -- not is_set(ConferenceURL) and -- TODO: keep this here? conference as part of cite web or cite podcast?
    -- not is_set(TranscriptURL) then -- TODO: remove? |transcript-url= and |transcript= has separate test
    -- Test if cite web or cite podcast |url= is missing or empty
    if in_array(config.CitationClass, {"web","podcast", "mailinglist"}) then
    table.insert( z.message_tail, { set_error( 'cite_web_url', {}, true ) } );
    table.insert( z.message_tail, { set_error( 'cite_web_url', {}, true ) } );
    end
    end
    Line 2,959: Line 3,277:
    end
    end


    local OriginalURL, OriginalFormat; -- TODO: swap chapter and title here so that archive applies to most specific if both are set?
    local OriginalURL, OriginalURLorigin, OriginalFormat; -- TODO: swap chapter and title here so that archive applies to most specific if both are set?
    DeadURL = DeadURL:lower(); -- used later when assembling archived text
    DeadURL = DeadURL:lower(); -- used later when assembling archived text
    if is_set( ArchiveURL ) then
    if is_set( ArchiveURL ) then
    if is_set (URL) then
    if is_set (URL) then
    OriginalURL = URL; -- save copy of original source URL
    OriginalURL = URL; -- save copy of original source URL
    OriginalURLorigin = URLorigin; -- name of url parameter for error messages
    OriginalFormat = Format; -- and original |format=
    OriginalFormat = Format; -- and original |format=
    if 'no' ~= DeadURL then -- if URL set then archive-url applies to it
    if 'no' ~= DeadURL then -- if URL set then archive-url applies to it
    Line 2,972: Line 3,291:
    elseif is_set (ChapterURL) then -- URL not set so if chapter-url is set apply archive url to it
    elseif is_set (ChapterURL) then -- URL not set so if chapter-url is set apply archive url to it
    OriginalURL = ChapterURL; -- save copy of source chapter's url for archive text
    OriginalURL = ChapterURL; -- save copy of source chapter's url for archive text
    OriginalURLorigin = ChapterURLorigin; -- name of chapter-url parameter for error messages
    OriginalFormat = ChapterFormat; -- and original |format=
    OriginalFormat = ChapterFormat; -- and original |format=
    if 'no' ~= DeadURL then
    if 'no' ~= DeadURL then
    ChapterURL = ArchiveURL -- swap-in the archive's url
    ChapterURL = ArchiveURL -- swap-in the archive's url
    URLorigin = A:ORIGIN('ArchiveURL') -- name of archive url parameter for error messages
    ChapterURLorigin = A:ORIGIN('ArchiveURL') -- name of archive-url parameter for error messages
    ChapterFormat = ArchiveFormat or ''; -- swap in archive's format
    ChapterFormat = ArchiveFormat or ''; -- swap in archive's format
    end
    end
    Line 2,981: Line 3,301:
    end
    end


    if in_array(config.CitationClass, {"web","news","journal","pressrelease","podcast", "newsgroup", 'arxiv'}) or
    if in_array(config.CitationClass, {'web','news','journal', 'magazine', 'pressrelease','podcast', 'newsgroup', 'arxiv'}) or -- if any of the 'periodical' cites except encyclopedia
    ('citation' == config.CitationClass and is_set (Periodical) and not is_set (Encyclopedia)) then
    ('citation' == config.CitationClass and is_set (Periodical) and not is_set (Encyclopedia)) then
    if is_set (Chapter) or is_set (TransChapter) or is_set (ChapterURL) or is_set (ScriptChapter) then -- chapter parameters not supported for these citation types
    local chap_param;
    table.insert( z.message_tail, { set_error( 'chapter_ignored', {A:ORIGIN ('Chapter')}, true ) } ); -- add error message
    if is_set (Chapter) then -- get a parameter name from one of these chapter related meta-parameters
    Chapter = ''; -- set them to empty string to be safe with concatenation
    chap_param = A:ORIGIN ('Chapter')
    elseif is_set (TransChapter) then
    chap_param = A:ORIGIN ('TransChapter')
    elseif is_set (ChapterURL) then
    chap_param = A:ORIGIN ('ChapterURL')
    elseif is_set (ScriptChapter) then
    chap_param = A:ORIGIN ('ScriptChapter')
    else is_set (ChapterFormat)
    chap_param = A:ORIGIN ('ChapterFormat')
    end
     
    if is_set (chap_param) then -- if we found one
    table.insert( z.message_tail, { set_error( 'chapter_ignored', {chap_param}, true ) } ); -- add error message
    Chapter = ''; -- and set them to empty string to be safe with concatenation
    TransChapter = '';
    TransChapter = '';
    ChapterURL = '';
    ChapterURL = '';
    ScriptChapter = '';
    ScriptChapter = '';
    ChapterFormat = '';
    end
    end
    else -- otherwise, format chapter / article title
    else -- otherwise, format chapter / article title
    Chapter = format_chapter_title (ScriptChapter, Chapter, TransChapter, ChapterURL, ChapterURLorigin);
    local no_quotes = false; -- default assume that we will be quoting the chapter parameter value
    if is_set (Contribution) and 0 < #c then -- if this is a contribution with contributor(s)
    if in_array (Contribution:lower(), cfg.keywords.contribution) then -- and a generic contribution title
    no_quotes = true; -- then render it unquoted
    end
    end
     
    Chapter = format_chapter_title (ScriptChapter, Chapter, TransChapter, ChapterURL, ChapterURLorigin, no_quotes); -- Contribution is also in Chapter
    if is_set (Chapter) then
    if is_set (Chapter) then
    if 'map' == config.CitationClass and is_set (TitleType) then
    if 'map' == config.CitationClass and is_set (TitleType) then
    Line 2,997: Line 3,338:
    end
    end
    Chapter = Chapter .. ChapterFormat .. sepc .. ' ';
    Chapter = Chapter .. ChapterFormat .. sepc .. ' ';
    elseif 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
    end
    end
    Line 3,005: Line 3,348:
    end
    end


    if in_array(config.CitationClass, {"web","news","journal","pressrelease","podcast", "newsgroup", "mailinglist", 'arxiv'}) or
    if in_array(config.CitationClass, {'web','news','journal', 'magazine', 'pressrelease','podcast', 'newsgroup', 'mailinglist', 'arxiv'}) or
    ('citation' == config.CitationClass and is_set (Periodical) and not is_set (Encyclopedia)) or
    ('citation' == config.CitationClass and is_set (Periodical) and not is_set (Encyclopedia)) or
    ('map' == config.CitationClass and is_set (Periodical)) then -- special case for cite map when the map is in a periodical treat as an article
    ('map' == config.CitationClass and is_set (Periodical)) then -- special case for cite map when the map is in a periodical treat as an article
    Line 3,035: Line 3,378:
    if is_set(Title) then
    if is_set(Title) then
    if not is_set(TitleLink) and is_set(URL) then  
    if not is_set(TitleLink) and is_set(URL) then  
    Title = external_link( URL, Title ) .. TransError .. Format;
    Title = external_link( URL, Title, URLorigin ) .. TransError .. Format;
    URL = "";
    URL = "";
    Format = "";
    Format = "";
    Line 3,049: Line 3,392:
    if is_set (Conference) then
    if is_set (Conference) then
    if is_set (ConferenceURL) then
    if is_set (ConferenceURL) then
    Conference = external_link( ConferenceURL, Conference );
    Conference = external_link( ConferenceURL, Conference, ConferenceURLorigin );
    end
    end
    Conference = sepc .. " " .. Conference .. ConferenceFormat;
    Conference = sepc .. " " .. Conference .. ConferenceFormat;
    Line 3,058: Line 3,401:
    if not is_set(Position) then
    if not is_set(Position) then
    local Minutes = A['Minutes'];
    local Minutes = A['Minutes'];
    local Time = A['Time'];
    if is_set(Minutes) then
    if is_set(Minutes) then
    if is_set (Time) then
    table.insert( z.message_tail, { set_error( 'redundant_parameters', {wrap_style ('parameter', 'minutes') .. ' and ' .. wrap_style ('parameter', 'time')}, true ) } );
    end
    Position = " " .. Minutes .. " " .. cfg.messages['minutes'];
    Position = " " .. Minutes .. " " .. cfg.messages['minutes'];
    else
    else
    local Time = A['Time'];
    if is_set(Time) then
    if is_set(Time) then
    local TimeCaption = A['TimeCaption']
    local TimeCaption = A['TimeCaption']
    Line 3,076: Line 3,423:
    Position = " " .. Position;
    Position = " " .. Position;
    At = '';
    At = '';
    end
    if not is_set(Page) then
    if is_set(Pages) then
    if is_set(Periodical) and
    not in_array(config.CitationClass, {"encyclopaedia","web","book","news","podcast"}) then
    Pages = ": " .. Pages;
    elseif tonumber(Pages) ~= nil then
    Pages = sepc .." " .. PPrefix .. Pages;
    else
    Pages = sepc .." " .. PPPrefix .. Pages;
    end
    end
    else
    if is_set(Periodical) and
    not in_array(config.CitationClass, {"encyclopaedia","web","book","news","podcast"}) then
    Page = ": " .. Page;
    else
    Page = sepc .." " .. PPrefix .. Page;
    end
    end
    end


    if 'map' == config.CitationClass then -- cite map oddity done after COinS call (and with other in-source locators)
    Page, Pages, Sheet, Sheets = format_pages_sheets (Page, Pages, Sheet, Sheets, config.CitationClass, Periodical_origin, sepc, NoPP, use_lowercase);
    if is_set (Sheet) or is_set (Sheets) then
    local err_msg1 = 'sheet=, &#124;sheets'; -- default error message in case any of page pages or at are set
    local err_msg2;
    if is_set (Page) or is_set (Pages) or is_set (At) then -- are any set?
    err_msg2 = 'page=, &#124;pages=, &#124;at'; -- a generic error message
    Page = ''; Pages = ''; At = '';
    elseif is_set (Sheet) and is_set (Sheets) then -- if both are set make error message
    err_msg1 = 'sheet';
    err_msg2 = 'sheets';
    end
    if is_set (err_msg2) then
    table.insert( z.message_tail, { set_error( 'redundant_parameters', {wrap_style ('parameter', err_msg1) .. ' and ' .. wrap_style ('parameter', err_msg2)}, true ) } ); -- add error message
    end
    if not is_set (Sheet) then -- do sheet static text and formatting; Sheet has priority over Sheets if both provided
    if is_set (Sheets) then
    if is_set (Periodical) then
    Sheet = ": Sheets " .. Sheets; -- because Sheet has priority, no need to support both later on
    else
    Sheet = sepc .. " Sheets " .. Sheets;
    end
    end
    else
    if is_set (Periodical) then
    Sheet = ": Sheet " .. Sheet;
    else
    Sheet = sepc .. " Sheet " .. Sheet;
    end
    end
    end
    end


    At = is_set(At) and (sepc .. " " .. At) or "";
    At = is_set(At) and (sepc .. " " .. At) or "";
    Line 3,170: Line 3,467:
    Edition = '';
    Edition = '';
    end
    end
    Issue = is_set(Issue) and (" (" .. Issue .. ")") or "";
     
    Series = is_set(Series) and (sepc .. " " .. Series) or "";
    Series = is_set(Series) and (sepc .. " " .. Series) or "";
    OrigYear = is_set(OrigYear) and (" [" .. OrigYear .. "]") or "";
    OrigYear = is_set(OrigYear) and (" [" .. OrigYear .. "]") or "";
    Agency = is_set(Agency) and (sepc .. " " .. Agency) or "";
    Agency = is_set(Agency) and (sepc .. " " .. Agency) or "";


    if is_set(Volume) then
    Volume = format_volume_issue (Volume, Issue, config.CitationClass, Periodical_origin, sepc, use_lowercase);
    if ( mw.ustring.len(Volume) > 4 )
      then Volume = sepc .." " .. Volume;
      else Volume = " <b>" .. hyphen_to_dash(Volume) .. "</b>";
    end
    end


    ------------------------------------ totally unrelated data
    ------------------------------------ totally unrelated data
    Line 3,225: Line 3,517:


    if is_set(Quote) then
    if is_set(Quote) then
    if Quote:sub(1,1) == '"' and Quote:sub(-1,-1) == '"' 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);
    Quote = Quote:sub(2,-2); -- strip them off
    end
    end
    Quote = sepc .." " .. wrap_style ('quoted-text', Quote ); -- wrap in <q>...</q> tags
    Quote = sepc .." " .. wrap_style ('quoted-text', Quote ); -- wrap in <q>...</q> tags
    PostScript = ""; -- CS1 does not supply terminal punctuation when |quote= is set
    PostScript = ""; -- cs1|2 does not supply terminal punctuation when |quote= is set
    end
    end
    Line 3,241: Line 3,533:
    if sepc ~= "." then arch_text = arch_text:lower() end
    if sepc ~= "." then arch_text = arch_text:lower() end
    Archived = sepc .. " " .. substitute( cfg.messages['archived-not-dead'],
    Archived = sepc .. " " .. substitute( cfg.messages['archived-not-dead'],
    { external_link( ArchiveURL, arch_text ) .. ArchiveFormat, ArchiveDate } );
    { external_link( ArchiveURL, arch_text, A:ORIGIN('ArchiveURL') ) .. ArchiveFormat, ArchiveDate } );
    if not is_set(OriginalURL) then
    if not is_set(OriginalURL) then
    Archived = Archived .. " " .. set_error('archive_missing_url');    
    Archived = Archived .. " " .. set_error('archive_missing_url');    
    Line 3,248: Line 3,540:
    local arch_text = cfg.messages['archived-dead'];
    local arch_text = cfg.messages['archived-dead'];
    if sepc ~= "." then arch_text = arch_text:lower() end
    if sepc ~= "." then arch_text = arch_text:lower() end
    -- if 'usurped' == DeadURL then -- when original has unsuitable content do not link
    if in_array (DeadURL, {'unfit', 'usurped'}) then
    if in_array (DeadURL, {'unfit', 'usurped'}) then
    Archived = sepc .. " " .. 'Archived from the original on ' .. ArchiveDate; -- format already styled
    Archived = sepc .. " " .. 'Archived from the original on ' .. ArchiveDate; -- format already styled
    else -- DeadURL is empty, 'yes', 'true', or 'y'
    else -- DeadURL is empty, 'yes', 'true', or 'y'
    Archived = sepc .. " " .. substitute( arch_text,
    Archived = sepc .. " " .. substitute( arch_text,
    { external_link( OriginalURL, cfg.messages['original'] ) .. OriginalFormat, ArchiveDate } ); -- format already styled
    { external_link( OriginalURL, cfg.messages['original'], OriginalURLorigin ) .. OriginalFormat, ArchiveDate } ); -- format already styled
    end
    end
    else
    else
    Line 3,276: Line 3,567:
    end
    end
    if sepc == '.' then
    if sepc == '.' then
    Lay = sepc .. " " .. external_link( LayURL, cfg.messages['lay summary'] ) .. LayFormat .. LaySource .. LayDate
    Lay = sepc .. " " .. external_link( LayURL, cfg.messages['lay summary'], A:ORIGIN('LayURL') ) .. LayFormat .. LaySource .. LayDate
    else
    else
    Lay = sepc .. " " .. external_link( LayURL, cfg.messages['lay summary']:lower() ) .. LayFormat .. LaySource .. LayDate
    Lay = sepc .. " " .. external_link( LayURL, cfg.messages['lay summary']:lower(), A:ORIGIN('LayURL') ) .. LayFormat .. LaySource .. LayDate
    end
    end
    elseif is_set (LayFormat) then -- Test if |lay-format= is given without giving a |lay-url=
    elseif is_set (LayFormat) then -- Test if |lay-format= is given without giving a |lay-url=
    Line 3,286: Line 3,577:
    if is_set(Transcript) then
    if is_set(Transcript) then
    if is_set(TranscriptURL) then
    if is_set(TranscriptURL) then
    Transcript = external_link( TranscriptURL, Transcript );
    Transcript = external_link( TranscriptURL, Transcript, TranscriptURLorigin );
    end
    end
    Transcript = sepc .. ' ' .. Transcript .. TranscriptFormat;
    Transcript = sepc .. ' ' .. Transcript .. TranscriptFormat;
    Line 3,360: Line 3,651:
    -- not to keep reassigning to the same string variable over and over.
    -- not to keep reassigning to the same string variable over and over.


    local tcommon
    local tcommon;
    local tcommon2; -- used for book cite when |contributor= is set
    if in_array(config.CitationClass, {"journal","citation"}) and is_set(Periodical) then
    if in_array(config.CitationClass, {"journal","citation"}) and is_set(Periodical) then
    if is_set(Others) then Others = Others .. sepc .. " " end
    if is_set(Others) then Others = Others .. sepc .. " " end
    tcommon = safe_join( {Others, Title, TitleNote, Conference, Periodical, Format, TitleType, Series,  
    tcommon = safe_join( {Others, Title, TitleNote, Conference, Periodical, Format, TitleType, Series,  
    Language, Edition, Publisher, Agency, Volume, Issue}, sepc );
    Language, Edition, Publisher, Agency, Volume}, sepc );
    elseif in_array(config.CitationClass, {"book","citation"}) and not is_set(Periodical) then -- special cases for book cites
    if 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
    elseif 'map' == config.CitationClass then -- special cases for cite map
    if is_set (Chapter) then -- map in a book; TitleType is part of Chapter
    if 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 );
    tcommon = safe_join( {Title, Format, Edition, Scale, Series, Language, Cartography, Others, Publisher, Volume}, sepc );
    elseif is_set (Periodical) then -- map in a periodical
    elseif is_set (Periodical) then -- map in a periodical
    tcommon = safe_join( {Title, TitleType, Format, Periodical, Scale, Series, Language, Cartography, Others, Publisher, Volume, Issue}, sepc );
    tcommon = safe_join( {Title, TitleType, Format, Periodical, Scale, Series, Language, Cartography, Others, Publisher, Volume}, sepc );
    else -- a sheet or stand-alone map
    else -- a sheet or stand-alone map
    tcommon = safe_join( {Title, TitleType, Format, Edition, Scale, Series, Language, Cartography, Others, Publisher}, sepc );
    tcommon = safe_join( {Title, TitleType, Format, Edition, Scale, Series, Language, Cartography, Others, Publisher}, sepc );
    Line 3,379: Line 3,680:
    else -- all other CS1 templates
    else -- all other CS1 templates
    tcommon = safe_join( {Title, TitleNote, Conference, Periodical, Format, TitleType, Series, Language,  
    tcommon = safe_join( {Title, TitleNote, Conference, Periodical, Format, TitleType, Series, Language,  
    Volume, Issue, Others, Edition, Publisher, Agency}, sepc );
    Volume, Others, Edition, Publisher, Agency}, sepc );
    end
    end
    Line 3,390: Line 3,691:
    local idcommon = safe_join( { ID_list, URL, Archived, AccessDate, Via, SubscriptionRequired, Lay, Quote }, sepc );
    local idcommon = safe_join( { ID_list, URL, Archived, AccessDate, Via, SubscriptionRequired, Lay, Quote }, sepc );
    local text;
    local text;
    local pgtext = Position .. Sheet .. Page .. Pages .. At;
    local pgtext = Position .. Sheet .. Sheets .. Page .. Pages .. At;
     
    if is_set(Date) then
    if is_set (Authors) or is_set (Editors) then -- date follows authors or editors when authors not set
    Date = " (" .. Date ..")" .. OrigYear .. sepc .. " "; -- in paranetheses
    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 .. OrigYear; -- Date does not begin with sepc
    else
    Date = sepc .. " " .. Date .. OrigYear; -- Date begins with sepc
    end
    end
    end
    if is_set(Authors) then
    if is_set(Authors) then
    if is_set(Coauthors) then
    if is_set(Coauthors) then
    local sep = '; ';
    if 'vanc' == NameListFormat then -- separate authors and coauthors with proper name-list-separator
    if 'vanc' == NameListFormat then
    Authors = Authors .. ', ' .. Coauthors;
    sep = ', ';
    else
    Authors = Authors .. '; ' .. Coauthors;
    end
    end
    Authors = Authors .. sep .. Coauthors;
    end
    end
    if is_set(Date) then
    if not is_set (Date) then -- when date is set it's in parentheses; no Authors termination
    Date = " ("..Date..")" .. OrigYear .. sepc .. " "
    Authors = terminate_name_list (Authors, sepc); -- when no date, terminate with 0 or 1 sepc and a space
    elseif string.sub(Authors,-1,-1) == sepc then
    Authors = Authors .. " "
    else
    Authors = Authors .. sepc .. " "
    end
    end
    if is_set(Editors) then
    if is_set(Editors) then
    local in_text = " ";
    local in_text = " ";
    local post_text = "";
    local post_text = "";
    if is_set(Chapter) then
    if is_set(Chapter) and 0 == #c then
    in_text = in_text .. cfg.messages['in'] .. " "
    in_text = in_text .. cfg.messages['in'] .. " "
    if (sepc ~= '.') then in_text = in_text:lower() end -- lowercase for cs2
    else
    else
    if EditorCount <= 1 then
    if EditorCount <= 1 then
    Line 3,419: Line 3,728:
    end
    end
    end  
    end  
    if (sepc ~= '.') then in_text = in_text:lower() end
    Editors = terminate_name_list (in_text .. Editors .. post_text, sepc); -- terminate with 0 or 1 sepc and a space
    Editors = in_text .. Editors .. post_text;
    end
    if (string.sub(Editors,-1,-1) == sepc) or (string.sub(Editors,-3,-1) == sepc .. ']]') then -- if last editor name ends with sepc char
    if is_set (Contributors) then -- book cite and we're citing the intro, preface, etc
    Editors = Editors .. " "; -- don't add another
    local by_text = sepc .. ' ' .. cfg.messages['by'] .. ' ';
    else
    if (sepc ~= '.') then by_text = by_text:lower() end -- lowercase for cs2
    Editors = Editors .. sepc .. " " -- otherwise terninate the editor list
    Authors = by_text .. Authors; -- author follows title so tweak it here
    if is_set (Editors) 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 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
    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
    end
    text = safe_join( {Authors, Date, Chapter, Place, Editors, tcommon }, sepc );
    text = safe_join( {text, pgtext, idcommon}, sepc );
    elseif is_set(Editors) then
    elseif is_set(Editors) then
    if is_set(Date) then
    if is_set(Date) then
    Line 3,436: Line 3,751:
    Editors = Editors .. ", " .. cfg.messages['editors'];
    Editors = Editors .. ", " .. cfg.messages['editors'];
    end
    end
    Date = " (" .. Date ..")" .. OrigYear .. sepc .. " "
    else
    else
    if EditorCount <= 1 then
    if EditorCount <= 1 then
    Line 3,444: Line 3,758:
    end
    end
    end
    end
    text = safe_join( {Editors, Date, Chapter, Place, tcommon}, sepc );
    text = safe_join( {Editors, Date, Chapter, Place, tcommon, pgtext, idcommon}, sepc );
    text = safe_join( {text, pgtext, idcommon}, sepc );
    else
    else
    if is_set(Date) then
    if ( string.sub(tcommon,-1,-1) ~= sepc )
      then Date = sepc .." " .. Date .. OrigYear
      else Date = " " .. Date .. OrigYear
    end
    end
    if config.CitationClass=="journal" and is_set(Periodical) then
    if config.CitationClass=="journal" and is_set(Periodical) then
    text = safe_join( {Chapter, Place, tcommon}, sepc );
    text = safe_join( {Chapter, Place, tcommon, pgtext, Date, idcommon}, sepc );
    text = safe_join( {text, pgtext, Date, idcommon}, sepc );
    else
    else
    text = safe_join( {Chapter, Place, tcommon, Date}, sepc );
    text = safe_join( {Chapter, Place, tcommon, Date, pgtext, idcommon}, sepc );
    text = safe_join( {text, pgtext, idcommon}, sepc );
    end
    end
    end
    end
    Line 3,479: Line 3,784:
    end
    end
    if is_set(Ref) and Ref:lower() ~= "none" then
    if is_set(Ref) and Ref:lower() ~= "none" then -- set reference anchor if appropriate
    local id = Ref
    local id = Ref
    if ( "harv" == Ref ) then
    if ('harv' == Ref ) then
    local names = {} --table of last names & year
    local namelist = {}; -- holds selected contributor, author, editor name list
    if #a > 0 then
    -- local year = first_set (Year, anchor_year); -- Year first for legacy citations and for YMD dates that require disambiguation
    for i,v in ipairs(a) do
    local year = first_set ({Year, anchor_year}, 2); -- Year first for legacy citations and for YMD dates that require disambiguation
    names[i] = v.last
     
    if i == 4 then break end
    if #c > 0 then -- if there is a contributor list
    end
    namelist = c; -- select it
    elseif #e > 0 then
    elseif #a > 0 then -- or an author list
    for i,v in ipairs(e) do
    namelist = a;
    names[i] = v.last
    elseif #e > 0 then -- or an editor list
    if i == 4 then break end
    namelist = e;
    end
    end
    end
    names[ #names + 1 ] = first_set(Year, anchor_year); -- Year first for legacy citations and for YMD dates that require disambiguation
    id = anchor_id (namelist, year); -- go make the CITEREF anchor
    id = anchor_id(names)
    end
    end
    options.id = id;
    options.id = id;
    Line 3,514: Line 3,817:
    local empty_span = '<span style="display:none;">&nbsp;</span>';
    local empty_span = '<span style="display:none;">&nbsp;</span>';
    -- Note: Using display: none on then COinS span breaks some clients.
    -- Note: Using display: none on the COinS span breaks some clients.
    local OCinS = '<span title="' .. OCinSoutput .. '" class="Z3988">' .. empty_span .. '</span>';
    local OCinS = '<span title="' .. OCinSoutput .. '" class="Z3988">' .. empty_span .. '</span>';
    text = text .. OCinS;
    text = text .. OCinS;
    Line 3,555: Line 3,858:
    end
    end


    -- This is used by templates such as {{cite book}} to create the actual citation text.
    --[[--------------------------< 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 nonprintable or invisible characters.  The search stops at the first match.
     
    Sometime after this module is done with rendering a citation, some C0 control characters are replaced with the
    replacement character.  That replacement character is not detected by this test though it is visible to readers
    of the rendered citation.  This function will detect the replacement character when it is part of the wikisource.
     
    Output of this function is an error message that identifies the character or the Unicode group that the character
    belongs to along with its position in the parameter value.
     
    ]]
     
    local function has_invisible_chars (param, v)
    local position = '';
    local i=1;
     
    while cfg.invisible_chars[i] do
    local char=cfg.invisible_chars[i][1] -- the character or group name
    local pattern=cfg.invisible_chars[i][2] -- the pattern used to find it
    position = mw.ustring.find (v, pattern) -- see if the parameter value contains characters that match the pattern
    if position then
    table.insert( z.message_tail, { set_error( 'invisible_char', {char, wrap_style ('parameter', param), position}, true ) } ); -- add error message
    return; -- and done with this parameter
    end
    i=i+1; -- bump our index
    end
    end
     
     
    --[[--------------------------< Z . C I T A T I O N >----------------------------------------------------------
     
    This is used by templates such as {{cite book}} to create the actual citation text.
     
    ]]
     
    function z.citation(frame)
    function z.citation(frame)
    local pframe = frame:getParent()
    local pframe = frame:getParent()
    Line 3,618: Line 3,956:
    end
    end
    end
    end
    -- if #suggestions == 0 then
    -- suggestions = mw.loadData( 'Module:Citation/CS1/Suggestions' );
    -- end
    -- if suggestions[ k:lower() ] ~= nil then
    -- error_text, error_state = set_error( 'parameter_ignored_suggest', {k, suggestions[ k:lower() ]}, true );
    -- else
    -- error_text, error_state = set_error( 'parameter_ignored', {k}, true );
    -- end
    end    
    end    
    if error_text ~= '' then
    if error_text ~= '' then
    Line 3,636: Line 3,966:
    end
    end
    end
    end
     
    for k, v in pairs( args ) do
    has_invisible_chars (k, v)
    end
    return citation0( config, args)
    return citation0( config, args)
    end
    end


    return z
    return z