Module:Citation/CS1

    From Nonbinary Wiki
    Revision as of 11:29, 3 September 2014 by m>It Is Me Here (Changed protection level of Module:Citation/CS1: High-risk Lua module ([Edit=Allow only administrators] (indefinite) [Move=Allow only administrators] (indefinite)) [cascading])

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

    local z = {
    	error_categories = {};
    	error_ids = {};
    	message_tail = {};
    }
    
    -- Whether variable is set or not
    function is_set( var )
    	return not (var == nil or var == '');
    end
    
    -- First set variable or nil if none
    function first_set(...)
    	local list = {...};
    	for _, var in pairs(list) do
    		if is_set( var ) then
    			return var;
    		end
    	end
    end
    
    -- Whether needle is in haystack
    function inArray( needle, haystack )
    	if needle == nil then
    		return false;
    	end
    	for n,v in ipairs( haystack ) do
    		if v == needle then
    			return n;
    		end
    	end
    	return false;
    end
    
    --[[
    Categorize and emit an error message when the citation contains one or more deprecated parameters.  Because deprecated parameters (currently |day=, |month=,
    |coauthor=, and |coauthors=) aren't related to each other and because these parameters may be concatenated into the variables used by |date= and |author#= (and aliases)
    details of which parameter caused the error message are not provided.  Only one error message is emitted regardless of the number of deprecated parameters in the citation.
    ]]
    function deprecated_parameter()
    	if true ~= Page_in_deprecated_cat then	-- if we haven't been here before then set a 
    		Page_in_deprecated_cat=true;		-- sticky flag so that if there are more than one deprecated parameter the category is added only once
    --		table.insert( z.message_tail, { seterror( 'deprecated_params', {error_message}, true ) } );		-- add error message
    		table.insert( z.message_tail, { seterror( 'deprecated_params', {}, true ) } );		-- add error message
    	end
    end
    
    -- Populates numbered arguments in a message string using an argument table.
    function substitute( msg, args )
    --	return args and tostring( mw.message.newRawMessage( msg, args ) ) or msg;
    	return args and mw.message.newRawMessage( msg, args ):plain() or msg;
    end
    
    --[[
    Apply kerning to open the space between the quote mark provided by the Module and a leading or trailing quote mark contained in a |title= or |chapter= parameter's value.
    This function will positive kern  either single or double quotes:
    	"'Unkerned title with leading and trailing single quote marks'"
    	" 'Kerned title with leading and trailing single quote marks' " (in real life the kerning isn't as wide as this example)
    ]]
    function kern_quotes (str)
    	local left='<span style="padding-left:0.2em;">%1</span>';		-- spacing to use when title contains leading single or double quote mark
    	local right='<span style="padding-right:0.2em;">%1</span>';		-- spacing to use when title contains trailing single or double quote mark
    	
    	if  str:match ("^[\"\'][^\']") then
    		str = string.gsub( str, "^[\"\']", left, 1 );				-- replace (captured) leading single or double quote with left-side <span>
    	end
    	if str:match ("[^\'][\"\']$") then
    		str = string.gsub( str, "[\"\']$", right, 1 );			-- replace (captured) trailing single or double quote with right-side <span>
    	end
    	return str;
    end
    
    -- Wraps a string using a message_list configuration taking one argument
    function wrap( key, str, lower )
    	if not is_set( str ) then
    		return "";
    	elseif inArray( key, { 'italic-title', 'trans-italic-title' } ) then
    		str = safeforitalics( str );
    	end
    	if lower == true then
    		return substitute( cfg.messages[key]:lower(), {str} );
    	else
    		return substitute( cfg.messages[key], {str} );
    	end		
    end
    
    --[[
    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.
    ]]
    function argument_wrapper( args )
    	local origin = {};
    	
    	return setmetatable({
    		ORIGIN = function( self, k )
    			local dummy = self[k]; --force the variable to be loaded.
    			return origin[k];
    		end
    	},
    	{
    		__index = function ( tbl, k )
    			if origin[k] ~= nil then
    				return nil;
    			end
    			
    			local args, list, v = args, cfg.aliases[k];
    			
    			if type( list ) == 'table' then
    				v, origin[k] = selectone( 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
    
    --[[
    Looks for a parameter's name in the whitelist.
    
    Parameters in the whitelist can have three values:
    	true - active, supported parameters
    	false - deprecated, supported parameters
    	nil - unsupported parameters
    ]]
    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 ();				-- 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 ();				-- parameter is deprecated but still supported
    		return true;
    	end
    	
    	return false;								-- Not supported because not found or name is set to nil
    end
    
    -- Formats a comment for error trapping
    function errorcomment( content, hidden )
    	return wrap( hidden and 'hidden-error' or 'visible-error', content );
    end
    
    --[[
    Sets an error condition and returns the appropriate error message.  The actual placement
    of the error message in the output is the responsibility of the calling function.
    ]]
    function seterror( error_id, arguments, raw, prefix, suffix )
    	local error_state = cfg.error_conditions[ error_id ];
    	
    	prefix = prefix or "";
    	suffix = suffix or "";
    	
    	if error_state == nil then
    		error( cfg.messages['undefined_error'] );
    	elseif is_set( error_state.category ) then
    		table.insert( z.error_categories, error_state.category );
    	end
    	
    	local message = substitute( error_state.message, arguments );
    	
    	message = message .. " ([[" .. cfg.messages['help page link'] .. 
    		"#" .. error_state.anchor .. "|" ..
    		cfg.messages['help page label'] .. "]])";
    	
    	z.error_ids[ error_id ] = true;
    	if inArray( error_id, { 'bare_url_missing_title', 'trans_missing_title' } )
    			and z.error_ids['citation_missing_title'] then
    		return '', false;
    	end
    	
    	message = table.concat({ prefix, message, suffix });
    	
    	if raw == true then
    		return message, error_state.hidden;
    	end		
    		
    	return errorcomment( message, error_state.hidden );
    end
    
    -- Formats a wiki style external link
    function externallinkid(options)
    	local url_string = options.id;
    	if options.encode == true or options.encode == nil then
    		url_string = mw.uri.encode( url_string );
    	end
    	return mw.ustring.format( '[[%s|%s]]%s[%s%s%s %s]',
    		options.link, options.label, options.separator or "&nbsp;",
    		options.prefix, url_string, options.suffix or "",
    		mw.text.nowiki(options.id)
    	);
    end
    
    -- Formats a wiki style internal link
    function internallinkid(options)
    	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
    
    -- Format an external link with error checking
    function externallink( URL, label, source )
    	local error_str = "";
    	if not is_set( label ) then
    		label = URL;
    		if is_set( source ) then
    			error_str = seterror( 'bare_url_missing_title', { wrap( 'parameter', source ) }, false, " " );
    		else
    			error( cfg.messages["bare_url_no_origin"] );
    		end			
    	end
    	if not checkurl( URL ) then
    		error_str = seterror( 'bad_url', {}, false, " " ) .. error_str;
    	end
    	return table.concat({ "[", URL, " ", safeforurl( label ), "]", error_str });
    end
    
    -- Formats a link to Amazon
    function amazon(id, domain)
    	if not is_set(domain) then 
    		domain = "com"
    	elseif ( "jp" == domain or "uk" == domain ) then
    		domain = "co." .. domain
    	end
    	local handler = cfg.id_handlers['ASIN'];
    	return externallinkid({link = handler.link,
    		label=handler.label , prefix="//www.amazon."..domain.."/dp/",id=id,
    		encode=handler.encode, separator = handler.separator})
    end
    
    --[[
    format and error check arXiv identifier.  There are two valid forms of the identifier:
    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 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
    ]]
    
    function arxiv (id)
    	local handler = cfg.id_handlers['ARXIV'];
    	local year, month, version;
    	local err_cat = ""
    	
    	year, month, version = id:match("^%a[%a%.%-]+/([90]%d)([01]%d)%d%d%d([v%d]*)$");				-- test for the 9108-0703 format
    	if not year then		-- arXiv id is not proper 9108-0703 form
    		year, month, version = id:match("^(%d%d)([01]%d)%.%d%d%d%d([v%d]*)$");	-- test for the 0704- format
    		if not year then	
    			err_cat = ' ' .. seterror( 'bad_arxiv' );							-- arXiv id doesn't match either format
    		else	-- id is the 0704- format
    			year = tonumber(year);
    			month = tonumber(month);
    			if ((7 > year) or (1 > month and 12 < month)) or					-- is year invalid or is month invalid? (doesn't test for future years)
    				((7 == year) and (4 > month)) or								-- when year is 07, is month invalid (before April)?
    				is_set (version) and nil == version:match("v%d+") then			-- is version proper format of single 'v' followed by digits?
    					err_cat = ' ' .. seterror( 'bad_arxiv' );					-- set error message
    			end
    		end
    	else	-- id is the 9108-0703 format; are the date values ok
    		year = tonumber(year);
    		month = tonumber(month);
    		if ((91 > year and 7 < year) or (1 > month and 12 < month)) or			-- if invalid year or invalid month
    			((91 == year and 8 > month) or (7 == year and 3 < month)) or 		-- if years ok, are starting and ending months ok?
    				is_set (version) and nil == version:match("v%d+") then			-- is version proper format of single 'v' followed by digits?
    					err_cat = ' ' .. seterror( 'bad_arxiv' );					-- set error message
    		end
    	end
    
    	return externallinkid({link = handler.link, label = handler.label,
    			prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode}) .. err_cat;
    end
    
    --[[
    lccn normalization (http://www.loc.gov/marc/lccn-namespace.html#normalization)
    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.
    
    Returns a normalized lccn for lccn() to validate.  There is no error checking (step 3.b.1) performed in this function.
    ]]
    
    function normalize_lccn (lccn)
    	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 prefix
    	local suffix
    	prefix, suffix = lccn:match ("(.+)%-(.+)");						-- 3.a remove hyphen by splitting the string into prefix and suffix
    
    	if nil ~= suffix then											-- if there was a hyphen
    		suffix=string.rep("0", 6-string.len (suffix)) .. suffix;	-- 3.b.2 left fill the suffix with 0s if suffix length less than 6
    		lccn=prefix..suffix;										-- reassemble the lccn
    	end
    	
    	return lccn;
    	end
    
    --[[
    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
    length = 9 then lccn[1] is alpha
    length = 10 then lccn[1] and lccn[2] are both alpha or both digits
    length = 11 then lccn[1] is alpha, lccn[2] and lccn[3] are both alpha or both digits
    length = 12 then lccn[1] and lccn[2] are both alpha
    
    ]]
    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
    
    	id = normalize_lccn (id);							-- get canonical form (no whitespace, hyphens, forward slashes)
    	local len = id:len();								-- get the length of the lccn
    
    	if 8 == len then
    		if id:match("[^%d]") then						-- if LCCN has anything but digits (nil if only digits)
    			err_cat = ' ' .. seterror( 'bad_lccn' );	-- set an error message
    		end
    	elseif 9 == len then								-- LCCN should be adddddddd
    		if nil == id:match("%a%d%d%d%d%d%d%d%d") then			-- does it match our pattern?
    			err_cat = ' ' .. seterror( '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("^%a%a%d%d%d%d%d%d%d%d") then	-- ... see if it matches our pattern
    				err_cat = ' ' .. seterror( 'bad_lccn' );	-- no match, set an error message
    			end
    		end
    	elseif 11 == len then								-- LCCN should be aaadddddddd or adddddddddd
    		if not (id:match("^%a%a%a%d%d%d%d%d%d%d%d") or id:match("^%a%d%d%d%d%d%d%d%d%d%d")) then	-- see if it matches one of our patterns
    			err_cat = ' ' .. seterror( 'bad_lccn' );	-- no match, set an error message
    		end
    	elseif 12 == len then								-- LCCN should be aadddddddddd
    		if not id:match("^%a%a%d%d%d%d%d%d%d%d%d%d") then	-- see if it matches our pattern
    			err_cat = ' ' .. seterror( 'bad_lccn' );	-- no match, set an error message
    		end
    	else
    		err_cat = ' ' .. seterror( 'bad_lccn' );		-- wrong length, set an error message
    	end
    
    	if not is_set (err_cat) and nil ~= lccn:find ('%s') then
    		err_cat = ' ' .. seterror( 'bad_lccn' );		-- lccn contains a space, set an error message
    	end
    
    	return externallinkid({link = handler.link, label = handler.label,
    			prefix=handler.prefix,id=lccn,separator=handler.separator, encode=handler.encode}) .. err_cat;
    end
    
    --[[
    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
    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.
    ]]
    function pmid(id)
    	local test_limit = 30000000;						-- update this value as PMIDs approach
    	local handler = cfg.id_handlers['PMID'];
    	local err_cat =  '';								-- presume that PMID is valid
    	
    	if id:match("[^%d]") then							-- if PMID has anything but digits
    		err_cat = ' ' .. seterror( 'bad_pmid' );		-- set an error message
    	else												-- PMID 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 PMID is outside test limit boundaries
    			err_cat = ' ' .. seterror( 'bad_pmid' );	-- set an error message
    		end
    	end
    	
    	return externallinkid({link = handler.link, label = handler.label,
    			prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode}) .. err_cat;
    end
    
    --[[
    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 true; otherwise, returns false because the embargo has expired or |embargo= not set in this cite.
    ]]
    function is_embargoed(embargo)
    	if is_set(embargo) then
    		local lang = mw.getContentLanguage();
    		local good1, embargo_date, good2, todays_date;
    		good1, embargo_date = pcall( lang.formatDate, lang, 'U', embargo );
    		good2, todays_date = pcall( lang.formatDate, lang, 'U' );
    	
    		if good1 and good2 and tonumber( embargo_date ) >= tonumber( todays_date ) then	--is embargo date is in the future?
    			return true;	-- still embargoed
    		end
    	end
    	return false;			-- embargo expired or |embargo= not set
    end
    
    --[[
    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 specifies a date 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.
    
    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
    than test_limit; the value in local variable test_limit will need to be updated periodically as more PMCs are issued.
    ]]
    function pmc(id, embargo)
    	local test_limit = 5000000;							-- update this value as PMCs approach
    	local handler = cfg.id_handlers['PMC'];
    	local err_cat =  '';								-- presume that PMC is valid
    	
    	local text;
    
    	if id:match("[^%d]") then							-- if PMC has anything but digits
    		err_cat = ' ' .. seterror( '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 = ' ' .. seterror( 'bad_pmc' );		-- set an error message
    		end
    	end
    	
    	if is_embargoed(embargo) then
    		text="[[" .. handler.link .. "|" .. handler.label .. "]]:" .. handler.separator .. id .. err_cat;	--still embargoed so no external link
    	else
    		text = externallinkid({link = handler.link, label = handler.label,			--no embargo date, ok to link to article
    			prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode}) .. err_cat;
    	end
    	return text;
    end
    
    -- Formats a DOI and checks for DOI errors.
    
    -- DOI names contain two parts: prefix and suffix separated by a forward slash.
    --  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.
    
    -- DOI names are case-insensitive and can incorporate any printable Unicode characters so the test for spaces, endash,
    -- and terminal punctuation may not be technically correct but it appears, that in practice these characters are rarely if ever used in doi names.
    
    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 = externallinkid({link = handler.link, label = handler.label,
    			prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode})
    		inactive = "" 
    	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
    		cat = ' ' .. seterror( 'bad_doi' );
    	end
    	return text .. inactive .. cat 
    end
    
    -- Formats an OpenLibrary link, and checks for associated errors.
    function openlibrary(id)
    	local code = id:sub(-1,-1)
    	local handler = cfg.id_handlers['OL'];
    	if ( code == "A" ) then
    		return externallinkid({link=handler.link, label=handler.label,
    			prefix="http://openlibrary.org/authors/OL",id=id, separator=handler.separator,
    			encode = handler.encode})
    	elseif ( code == "M" ) then
    		return externallinkid({link=handler.link, label=handler.label,
    			prefix="http://openlibrary.org/books/OL",id=id, separator=handler.separator,
    			encode = handler.encode})
    	elseif ( code == "W" ) then
    		return externallinkid({link=handler.link, label=handler.label,
    			prefix= "http://openlibrary.org/works/OL",id=id, separator=handler.separator,
    			encode = handler.encode})
    	else
    		return externallinkid({link=handler.link, label=handler.label,
    			prefix= "http://openlibrary.org/OL",id=id, separator=handler.separator,
    			encode = handler.encode}) .. 
    			' ' .. seterror( 'bad_ol' );
    	end
    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
    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
    	
    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
    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.
    ]]
    function issn(id)
    	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;
    
    	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
    		valid_issn=false;										-- wrong length or improper character
    	else
    		valid_issn=is_valid_isxn(id, 8);						-- validate issn
    	end
    
    	if true == valid_issn then
    		id = string.sub( id, 1, 4 ) .. "-" .. string.sub( id, 5 );	-- if valid, display correctly formatted version
    	else
    		id = issn_copy;											-- if not valid, use the show the invalid issn with error message
    	end
    	
    	text = externallinkid({link = handler.link, label = handler.label,
    		prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode})
     
    	if false == valid_issn then
    		text = text .. ' ' .. seterror( 'bad_issn' )			-- add an error message if the issn is invalid
    	end 
    	
    	return text
    end
    
    --[[
    This function sets default title types (equivalent to the citation including |type=<default value>) for those citations that have defaults.
    Also handles the special case where it is desirable to omit the title type from the rendered citation (|type=none).
    ]]
    function set_titletype(cite_class, title_type)
    	if is_set(title_type) then
    		if "none" == title_type then
    			title_type = "";					-- if |type=none then type parameter not displayed
    		end
    		return title_type;						-- if |type= has been set to any other value use that value
    	end
    
    	if "AV-media-notes" == cite_class or "DVD-notes" == cite_class then		-- if this citation is cite AV media notes or cite DVD notes
    		return "Media notes";					-- display AV media notes / DVD media notes annotation
    
    	elseif "podcast" == cite_class then			-- if this citation is cite podcast
    		return "Podcast";						-- display podcast annotation
    
    	elseif "pressrelease" == cite_class then	-- if this citation is cite press release
    		return "Press release";					-- display press release annotation
    
    	elseif "techreport" == cite_class then		-- if this citation is cite techreport
    		return "Technical report";				-- display techreport annotation
    	
    	elseif "thesis" == cite_class then			-- if this citation is cite thesis (degree option handled after this function returns)
    			return "Thesis";					-- display simple thesis annotation (without |degree= modification)
    	end
    end
    
    --[[
    Determines whether a URL string is valid
    
    At present the only check is whether the string appears to 
    be prefixed with a URI scheme.  It is not determined whether 
    the URI scheme is valid or whether the URL is otherwise well 
    formed.
    ]]
    function checkurl( url_str )
    	-- Protocol-relative or URL scheme
    	return url_str:sub(1,2) == "//" or url_str:match( "^[^/]*:" ) ~= nil;
    end
    
    -- Removes irrelevant text and dashes from ISBN number
    -- Similar to that used for Special:BookSources
    function cleanisbn( isbn_str )
    	return isbn_str:gsub( "[^-0-9X]", "" );
    end
    
    -- Extract page numbers from external wikilinks in any of the |page=, |pages=, or |at= parameters for use in COinS.
    --TODO: Fix so this code supports urls like this:
    --	http://www.history.navy.mil/download/va125153.pdf#page=13 %w/:\.
    function get_coins_pages (pages)
    	if not is_set (pages) then return pages; end			-- if no page numbers then we're done
    	
    	while true do
    		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 = pattern:gsub("([%^%$%(%)%%%.%[%]%*%+%-%?])", "%%%1");	-- 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
    
    --[[
    ISBN-10 and ISSN validator code calculates checksum across all isbn/issn digits including the check digit. ISBN-13 is checked in checkisbn().
    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.
    ]]
    function is_valid_isxn (isxn_str, len)
    	local temp = 0;
    	isxn_str = { isxn_str:byte(1, len) };	-- make a table of bytes
    	len = len+1;							-- adjust to be a loop counter
    	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
    			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
    
    -- Determines whether an ISBN string is valid
    function checkisbn( isbn_str )
    	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 len == 10 then
    		if isbn_str:match( "^%d*X?$" ) == nil then return false; end
    		return is_valid_isxn(isbn_str, 10);
    	else
    		local temp = 0;
    		if isbn_str:match( "^97[89]%d*$" ) == nil then return false; end	-- isbn13 begins with 978 or 979
    		isbn_str = { isbn_str:byte(1, len) };
    		for i, v in ipairs( isbn_str ) do
    			temp = temp + (3 - 2*(i % 2)) * tonumber( string.char(v) );
    		end
    		return temp % 10 == 0;
    	end
    end
    
    -- Gets the display text for a wikilink like [[A|B]] or [[B]] gives B
    function removewikilink( str )
    	return (str:gsub( "%[%[([^%[%]]*)%]%]", function(l)
    		return l:gsub( "^[^|]*|(.*)$", "%1" ):gsub("^%s*(.-)%s*$", "%1");
    	end));
    end
    
    -- Escape sequences for content that will be used for URL descriptions
    function safeforurl( str )
    	if str:match( "%[%[.-%]%]" ) ~= nil then 
    		table.insert( z.message_tail, { seterror( 'wikilink_in_url', {}, true ) } );
    	end
    	
    	return str:gsub( '[%[%]\n]', {	
    		['['] = '&#91;',
    		[']'] = '&#93;',
    		['\n'] = ' ' } );
    end
    
    -- Converts a hyphen to a dash
    function hyphentodash( str )
    	if not is_set(str) or str:match( "[%[%]{}<>]" ) ~= nil then
    		return str;
    	end	
    	return str:gsub( '-', '–' );
    end
    
    -- Protects a string that will be wrapped in wiki italic markup '' ... ''
    function safeforitalics( str )
    	--[[ 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. ]]
    	
    	if not is_set(str) then
    		return str;
    	else
    		if str:sub(1,1) == "'" then str = "<span />" .. str; end
    		if str:sub(-1,-1) == "'" then str = str .. "<span />"; end
    		
    		-- Remove newlines as they break italics.
    		return str:gsub( '\n', ' ' );
    	end
    end
    
    --[[
    Joins a sequence of strings together while checking for duplicate separation characters.
    
    TODO: safejoin() has a flaw where it won't remove the duplicate character from a |title= / |url= combination.
    This is because by the time we get here, |title=http://somesite.com and |title=Document Title. have been combined:
    	[http://somesite.com and ''Document Title.'']
    so that now, the last character is not sepc but is ] (unless sepc == ']' which breaks the external link)
    ]]
    function safejoin( tbl, duplicate_char )
    	--[[
    	Note: we use string functions here, rather than ustring functions.
    	
    	This has considerably faster performance and should work correctly as 
    	long as the duplicate_char is strict ASCII.  The strings
    	in tbl may be ASCII or UTF8.
    	]]
    	
    	local str = '';
    	local comp = '';
    	local end_chr = '';
    	local trim;
    	for _, value in ipairs( tbl ) do
    		if value == nil then value = ''; end
    		
    		if str == '' then
    			str = value;
    		elseif value ~= '' then
    			if value:sub(1,1) == '<' then
    				-- Special case of values enclosed in spans and other markup.
    				comp = value:gsub( "%b<>", "" );
    			else
    				comp = value;
    			end
    			
    			if comp:sub(1,1) == duplicate_char then
    				trim = false;
    				end_chr = str:sub(-1,-1);
    				-- str = str .. "<HERE(enchr=" .. end_chr.. ")"
    				if end_chr == duplicate_char then
    					str = str:sub(1,-2);
    				elseif end_chr == "'" then
    					if str:sub(-3,-1) == duplicate_char .. "''" then
    						str = str:sub(1, -4) .. "''";
    					elseif str:sub(-5,-1) == duplicate_char .. "]]''" then
    						trim = true;
    					elseif str:sub(-4,-1) == duplicate_char .. "]''" then
    						trim = true;
    					end
    				elseif end_chr == "]" then
    					if str:sub(-3,-1) == duplicate_char .. "]]" then
    						trim = true;
    					elseif str:sub(-2,-1) == duplicate_char .. "]" then
    						trim = true;
    					end
    				elseif end_chr == " " then
    					if str:sub(-2,-1) == duplicate_char .. " " then
    						str = str:sub(1,-3);
    					end
    				end
    
    				if trim then
    					if value ~= comp then 
    						local dup2 = duplicate_char;
    						if dup2:match( "%A" ) then dup2 = "%" .. dup2; end
    						
    						value = value:gsub( "(%b<>)" .. dup2, "%1", 1 )
    					else
    						value = value:sub( 2, -1 );
    					end
    				end
    			end
    			str = str .. value;
    		end
    	end
    	return str;
    end  
    
    -- Attempts to convert names to initials.
    function reducetoinitials(first)
    	local initials = {}
    	local i = 0;										-- counter for number of initials
    	for word in string.gmatch(first, "%S+") do
    		table.insert(initials, string.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
    	return table.concat(initials)						-- Vancouver format does not include spaces.
    end
    
    -- Formats a list of people (e.g. authors / editors) 
    function listpeople(control, people)
    	local sep = control.sep;
    	local namesep = control.namesep
    	local format = control.format
    	local maximum = control.maximum
    	local lastauthoramp = control.lastauthoramp;
    	local text = {}
    	local etal = false;
    	
    	if sep:sub(-1,-1) ~= " " then sep = sep .. " " end
    	if maximum ~= nil and maximum < 1 then return "", 0; end
    	
    	for i,person in ipairs(people) do
    		if is_set(person.last) then
    			local mask = person.mask
    			local one
    			local sep_one = sep;
    			if maximum ~= nil 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 first = reducetoinitials(first) end
    					one = one .. namesep .. first 
    				end
    				if is_set(person.link) then one = "[[" .. person.link .. "|" .. one .. "]]" end
    				if is_set(person.link) and nil ~= person.link:find("//") then one = one .. " " .. seterror( 'bad_authorlink' ) end	-- check for url in author link;
    			end
    			table.insert( text, one )
    			table.insert( text, sep_one )
    		end
    	end
    
    	local count = #text / 2;
    	if count > 0 then 
    		if count > 1 and is_set(lastauthoramp) and not etal then
    			text[#text-2] = " & ";
    		end
    		text[#text] = nil; 
    	end
    	
    	local result = table.concat(text) -- construct list
    	if etal then 
    		local etal_text = cfg.messages['et al'];
    		result = result .. " " .. etal_text;
    	end
    	
    	-- if necessary wrap result in <span> tag to format in Small Caps
    	if ( "scap" == format ) then result = 
    		'<span class="smallcaps" style="font-variant:small-caps">' .. result .. '</span>';
    	end 
    	return result, count
    end
    
    -- Generates a CITEREF anchor ID.
    function anchorid( options )
    	return "CITEREF" .. table.concat( options );
    end
    
    --[[
    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=.
    ]]
    --Original function
    function extractnames(args, list_name)
        local names = {};
        local i = 1;
        local last;
     
        while true do
            last = selectone( args, cfg.aliases[list_name .. '-Last'], 'redundant_parameters', i );
            if not is_set(last) then
                -- just in case someone passed in an empty parameter
                break;
            end
            names[i] = {
                last = last,
                first = selectone( args, cfg.aliases[list_name .. '-First'], 'redundant_parameters', i ),
                link = selectone( args, cfg.aliases[list_name .. '-Link'], 'redundant_parameters', i ),
                mask = selectone( args, cfg.aliases[list_name .. '-Mask'], 'redundant_parameters', i )
            };
            i = i + 1;
        end
        return names;
    end
    
    --[[ Broken.  Editor CITEREF IDs are broken by this code (no editor list). Author CITEREF ID render correctly
    function extractnames(args, list_name)
    	local names = {};			-- table of names
    	local i = 1;				-- loop counter/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 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
    		names[i] =				-- search through args for name components beginning at 1
    			{
    			last = selectone( args, cfg.aliases[list_name .. '-Last'], 'redundant_parameters', i ),
    			first = selectone( args, cfg.aliases[list_name .. '-First'], 'redundant_parameters', i ),
    			link = selectone( args, cfg.aliases[list_name .. '-Link'], 'redundant_parameters', i ),
    			mask = selectone( args, cfg.aliases[list_name .. '-Mask'], 'redundant_parameters', i )
    			};
    		if names[i].first and not names[i].last then							-- if there is a firstn without a matching lastn
    			names[i].first = nil;												-- set first to nil so we don't confuse the implicit et al message code
    			table.insert( z.message_tail, { seterror( 'first_missing_last', {err_msg_list_name, i}, true ) } );	-- add this error message
    			break;																-- and done because lastn not found
    		elseif not names[i].first and not names[i].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																	-- last with or without a first
    			if 1 == count then													-- if the previous name was missing
    				table.insert( z.message_tail, { seterror( '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;																-- bump to the next name
    	end
    	return names;																-- all done, return our list of names
    end
    ]]
    
    
    
    -- Populates ID table from arguments using configuration settings
    function extractids( args )
    	local id_list = {};
    	for k, v in pairs( cfg.id_handlers ) do	
    		v = selectone( args, v.parameters, 'redundant_parameters' );
    		if is_set(v) then id_list[k] = v; end
    	end
    	return id_list;
    end
    
    -- Takes a table of IDs and turns it into a table of formatted ID outputs.
    function buildidlist( 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( id_list ) do
    		-- fallback to read-only cfg
    		handler = setmetatable( { ['id'] = v }, fallback(k) );
    		
    		if handler.mode == 'external' then
    			table.insert( new_list, {handler.label, externallinkid( handler ) } );
    		elseif handler.mode == 'internal' then
    			table.insert( new_list, {handler.label, internallinkid( 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 ) } ); 
    		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' 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 == 'ISSN' then
    			table.insert( new_list, {handler.label, issn( v ) } );
    		elseif k == 'ISBN' then
    			local ISBN = internallinkid( handler );
    			if not checkisbn( v ) and not is_set(options.IgnoreISBN) then
    				ISBN = ISBN .. seterror( 'bad_isbn', {}, false, " ", "" );
    			end
    			table.insert( new_list, {handler.label, ISBN } );				
    		else
    			error( cfg.messages['unknown_manual_ID'] );
    		end
    	end
    	
    	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
      
    -- Chooses one matching parameter from a list of parameters to consider
    -- Generates an error if more than one match is present.
    function selectone( args, possible, error_condition, index )
    	local value = nil;
    	local selected = '';
    	local error_list = {};
    	
    	if index ~= nil then index = tostring(index); end
    	
    	-- Handle special case of "#" replaced by empty string
    	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
    	
    	for _, v in ipairs( possible ) do
    		if index ~= nil then
    			v = v:gsub( "#", index );
    		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
    	
    	if #error_list > 0 then
    		local error_str = "";
    		for _, k in ipairs( error_list ) do
    			if error_str ~= "" then error_str = error_str .. cfg.messages['parameter-separator'] end
    			error_str = error_str .. wrap( 'parameter', k );
    		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( 'parameter', selected );
    		table.insert( z.message_tail, { seterror( error_condition, {error_str}, true ) } );
    	end
    	
    	return value, selected;
    end
    
    -- COinS metadata (see <http://ocoins.info/>) allows automated tools to parse
    -- the citation information.
    function COinS(data)
    	if 'table' ~= type(data) or nil == next(data) then
    		return '';
    	end
    	
    	local ctx_ver = "Z39.88-2004";
    	
    	-- treat table strictly as an array with only set values.
    	local OCinSoutput = setmetatable( {}, {
    		__newindex = function(self, key, value)
    			if is_set(value) then
    				rawset( self, #self+1, table.concat{ key, '=', mw.uri.encode( removewikilink( value ) ) } );
    			end
    		end
    	});
    	
    	if is_set(data.Chapter) then
    		OCinSoutput.rft_val_fmt = "info:ofi/fmt:kev:mtx:book";
    		OCinSoutput["rft.genre"] = "bookitem";
    		OCinSoutput["rft.btitle"] = data.Chapter;
    		OCinSoutput["rft.atitle"] = data.Title;
    	elseif is_set(data.Periodical) then
    		OCinSoutput.rft_val_fmt = "info:ofi/fmt:kev:mtx:journal";
    		OCinSoutput["rft.genre"] = "article";
    		OCinSoutput["rft.jtitle"] = data.Periodical;
    		OCinSoutput["rft.atitle"] = data.Title;
    	else
    		OCinSoutput.rft_val_fmt = "info:ofi/fmt:kev:mtx:book";
    		OCinSoutput["rft.genre"] = "book"
    		OCinSoutput["rft.btitle"] = data.Title;
    	end
    	
    	OCinSoutput["rft.place"] = data.PublicationPlace;
    	OCinSoutput["rft.date"] = data.Date;
    	OCinSoutput["rft.series"] = data.Series;
    	OCinSoutput["rft.volume"] = data.Volume;
    	OCinSoutput["rft.issue"] = data.Issue;
    	OCinSoutput["rft.pages"] = data.Pages;
    	OCinSoutput["rft.edition"] = data.Edition;
    	OCinSoutput["rft.pub"] = data.PublisherName;
    	
    	for k, v in pairs( data.ID_list ) do
    		local id, value = cfg.id_handlers[k].COinS;
    		if k == 'ISBN' then value = cleanisbn( 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
    			if is_set(last) then
    				OCinSoutput["rft.aulast"] = last;
    			end
    			if is_set(first) then 
    				OCinSoutput["rft.aufirst"] = first;
    			end
    		end
    		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
    	
    	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
    
    --[[
    This is the main function doing the majority of the citation
    formatting.
    ]]
    function citation0( config, args)
    	--[[ 
    	Load Input Parameters
    	The argument_wrapper facilitates the mapping of multiple
    	aliases to single internal variable.
    	]]
    	local A = argument_wrapper( args );
    
    	local i 
    	local PPrefix = A['PPrefix']
    	local PPPrefix = A['PPPrefix']
    	if is_set( A['NoPP'] ) then PPPrefix = "" PPrefix = "" end
    	
    	-- Pick out the relevant fields from the arguments.  Different citation templates
    	-- define different field names for the same underlying things.	
    	local Authors = A['Authors'];
    	local a = extractnames( args, 'AuthorList' );
    
    	local Coauthors = A['Coauthors'];
    	local Others = A['Others'];
    	local Editors = A['Editors'];
    	local e = extractnames( args, 'EditorList' );
    
    	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 BookTitle = A['BookTitle'];
    	local Conference = A['Conference'];
    	local TransTitle = A['TransTitle'];
    	local TitleNote = A['TitleNote'];
    	local TitleLink = A['TitleLink'];
    	local Chapter = A['Chapter'];
    	local ChapterLink = A['ChapterLink'];
    	local TransChapter = A['TransChapter'];
    	local TitleType = A['TitleType'];
    	local Degree = A['Degree'];
    	local Docket = A['Docket'];
    	local ArchiveURL = A['ArchiveURL'];
    	local URL = A['URL']
    	local URLorigin = A:ORIGIN('URL');
    	local ChapterURL = A['ChapterURL'];
    	local ChapterURLorigin = A:ORIGIN('ChapterURL');
    	local ConferenceURL = A['ConferenceURL'];
    	local ConferenceURLorigin = A:ORIGIN('ConferenceURL');
    	local Periodical = A['Periodical'];
    
    	local Series = A['Series'];
    	local Volume = A['Volume'];
    	local Issue = A['Issue'];
    	local Position = '';
    	local Page = A['Page'];
    	local Pages = hyphentodash( A['Pages'] );	
    	local At = A['At'];
    
    	local Edition = A['Edition'];
    	local PublicationPlace = A['PublicationPlace']
    	local Place = A['Place'];
    	
    	local PublisherName = A['PublisherName'];
    	local RegistrationRequired = A['RegistrationRequired'];
    	local SubscriptionRequired = A['SubscriptionRequired'];
    	local Via = A['Via'];
    	local AccessDate = A['AccessDate'];
    	local ArchiveDate = A['ArchiveDate'];
    	local Agency = A['Agency'];
    	local DeadURL = A['DeadURL']
    	local Language = A['Language'];
    	local Format = A['Format'];
    	local Ref = A['Ref'];
    	local DoiBroken = A['DoiBroken'];
    	local ID = A['ID'];
    	local ASINTLD = A['ASINTLD'];
    	local IgnoreISBN = A['IgnoreISBN'];
    	local Embargo = A['Embargo'];
    
    	local ID_list = extractids( args );
    --[[ Hide unfinished cite newsgroup code so that long delayed update can take place
    	-- special case for cite newsgroup which uses |id= for a usenet article or post id
    	-- |id= is not included in COinS so here we convert it to an ID that will be included in COinS
    	if ('newsgroup' == config.CitationClass) and (is_set (ID)) then
    		ID_list['USENETID']=ID;			-- add this new 'id' to the list of IDs
    		ID = '';						-- and unset
    	end
    ]]	
    	local Quote = A['Quote'];
    	local PostScript = A['PostScript'];
    
    	local LayURL = A['LayURL'];
    	local LaySource = A['LaySource'];
    	local Transcript = A['Transcript'];
    	local TranscriptURL = A['TranscriptURL'] 
    	local TranscriptURLorigin = A:ORIGIN('TranscriptURL');
    	local sepc = A['Separator'];
    
    	local LastAuthorAmp = A['LastAuthorAmp'];
    	local no_tracking_cats = A['NoTracking'];
    
    --these are used by cite interview
    	local Callsign = A['Callsign'];
    	local City = A['City'];
    	local Cointerviewers = A['Cointerviewers'];			-- deprecated
    	local Interviewer = A['Interviewer'];				-- deprecated
    	local Program = A['Program'];
    
    --local variables that are not cs1 parameters
    	local page_type;									-- is this needed?  Doesn't appear to be used anywhere;
    	local use_lowercase = ( sepc ~= '.' );
    	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 postscript default.
    	if not is_set (PostScript) then						-- if |postscript= has not been set (Postscript is nil which is the default for {{citation}}) and
    		if (config.CitationClass ~= "citation") then	-- this template is not a citation template
    			PostScript = '.';							-- must be a cite xxx template so set postscript to default (period)
    		end
    	else
    		if PostScript:lower() == 'none' then			-- if |postscript=none then
    			PostScript = '';							-- no postscript
    		end
    	end
    
    --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_set(no_tracking_cats) then				-- ignore if we are already not going to categorize this page
    		for k, v in pairs( cfg.uncategorized_namespaces ) do	-- otherwise, spin through the list of namespaces we don't include in error categories
    			if this_page.nsText == v then				-- if we find one
    				no_tracking_cats = "true";				-- set no_tracking_cats
    				break;									-- and we're done
    			end
    		end
    	end
    
    -- check for extra |page=, |pages= or |at= parameters. 
    	if is_set(Page) then
    		if is_set(Pages) or is_set(At) then
    			Page = Page .. " " .. seterror('extra_pages');	-- add error message
    			Pages = '';										-- unset the others
    			At = '';
    		end
    	elseif is_set(Pages) then
    		if is_set(At) then
    			Pages = Pages .. " " .. seterror('extra_pages');	-- add error messages
    			At = '';											-- unset
    		end
    	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
    	
    	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
    
    	|trans_title maps to |trans_chapter when |title is re-mapped
    
    All other combinations of |encyclopedia, |title, and |article are not modified
    ]]
    	if ( config.CitationClass == "encyclopaedia" ) then
    		if is_set(Periodical) then					-- Periodical is set when |encyclopedia is set
    			if is_set(Title) then
    				if not is_set(Chapter) then
    					Chapter = Title;				-- |encyclopedia and |title are set so map |title to |article and |encyclopedia to |title
    					TransChapter = TransTitle;
    					Title = Periodical;
    					Periodical = '';				-- redundant so unset
    					TransTitle = '';				-- redundant so unset
    				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
    
    --special cases for citation.
    	if (config.CitationClass == "citation") then		-- for citation templates
    		if not is_set (Ref) then						-- if |ref= is not set
    			Ref = "harv";								-- set default |ref=harv
    		end
    		if not is_set (sepc) then						-- if |separator= is not set
    			sepc = ',';									-- set citation separator to its default (comma)
    		end
    	else												-- not a citation template
    		if not is_set (sepc) then						-- if |separator= has not been set
    			sepc = '.';									-- set cite xxx separator to its default (period)
    		end
    	end
    
    -- check for special case where |separator=none
    	if 'none' == sepc:lower() then						-- if |separator=none
    		sepc = '';										-- then set it to an empty string
    	end
    
    -- Special case for cite techreport.
    	if (config.CitationClass == "techreport") then	-- special case for cite techreport
    		if is_set(Issue) then						-- cite techreport uses 'number', which other citations aliase to 'issue'
    			if not is_set(ID) then					-- can we use ID for the "number"?
    				ID = Issue;							-- yes, use it
    				Issue = "";							-- unset Issue so that "number" isn't duplicated in the rendered citation or COinS metadata
    			else									-- can't use ID so emit error message
    				ID = ID .. " " .. seterror('redundant_parameters', '<code>&#124;id=</code> and <code>&#124;number=</code>');
    			end
    		end	
    	end
    
    -- special case for cite interview
    	if (config.CitationClass == "interview") then
    		if is_set(Program) then
    			ID = ' ' .. Program;
    		end
    		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
    
    		if is_set(Interviewer) then
    			if is_set(TitleType) then
    				Others = ' ' .. TitleType .. ' with ' .. Interviewer;
    				TitleType = '';
    			else
    				Others = ' ' .. 'Interview with ' .. Interviewer;
    			end
    			if is_set(Cointerviewers) then
    				Others = Others .. sepc .. ' ' .. Cointerviewers;
    			end
    		else
    			Others = '(Interview)';
    		end
    	end
    
    --Account for the oddity that is {{cite journal}} with |pmc= set and |url= not set
    	if config.CitationClass == "journal" and not is_set(URL) and is_set(ID_list['PMC']) then
    		if not is_embargoed(Embargo) then
    			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
    
    -- Account for the oddity that is {{cite conference}}, before generation of COinS data.
    --TODO: if this is only for {{cite conference}}, shouldn't we be checking? (if config.CitationClass=='conference' then ...)
    	if is_set(BookTitle) then
    		Chapter = Title;
    		ChapterLink = TitleLink;
    		TransChapter = TransTitle;
    		Title = BookTitle;
    		TitleLink = '';
    		TransTitle = '';
    	end
    
    -- Account for the oddity that is {{cite episode}}, before generation of COinS data.
    --[[	-- {{cite episode}} is not currently supported by this module
    	if config.CitationClass == "episode" then
    		local AirDate = A['AirDate'];
    		local SeriesLink = A['SeriesLink'];
    		local Season = A['Season'];
    		local SeriesNumber = A['SeriesNumber'];
    		local Network = A['Network'];
    		local Station = A['Station'];
    		local s, n = {}, {};
    		local Sep = (first_set(A["SeriesSeparator"], A["Separator"]) or "") .. " ";
    		
    		if is_set(Issue) then table.insert(s, cfg.messages["episode"] .. " " .. Issue); Issue = ''; end
    		if is_set(Season) then table.insert(s, cfg.messages["season"] .. " " .. Season); end
    		if is_set(SeriesNumber) then table.insert(s, cfg.messages["series"] .. " " .. SeriesNumber); end
    		if is_set(Network) then table.insert(n, Network); end
    		if is_set(Station) then table.insert(n, Station); end
    		
    		Date = Date or AirDate;
    		Chapter = Title;
    		ChapterLink = TitleLink;
    		TransChapter = TransTitle;
    		Title = Series;
    		TitleLink = SeriesLink;
    		TransTitle = '';
    		
    		Series = table.concat(s, Sep);
    		ID = table.concat(n, Sep);
    	end
    -- end of {{cite episode}} stuff]]
    
    -- legacy: promote concatenation of |day=, |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 is_set(Date) then
    			local Month = A['Month'];
    			if is_set(Month) then
    				Date = Month .. " " .. Date;
    				local Day = A['Day']
    				if is_set(Day) then Date = Day .. " " .. Date end
    			end
    		elseif 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
    
    
    --[[
    Go test all of the date-holding parameters for valid MOS:DATE format and make sure that dates are real dates. This must be done before we do COinS because here is where
    we get the date used in the metadata.
    
    Date validation supporting code is in Module:Citation/CS1/Date_validation
    ]]
    	anchor_year, COinS_date, error_message = dates({['accessdate']=AccessDate, ['airdate']=AirDate, ['archivedate']=ArchiveDate, ['date']=Date, ['doi_brokendate']=DoiBroken,
    		['embargo']=Embargo, ['laydate']=LayDate, ['publicationdate']=PublicationDate, ['year']=Year});
    	if is_set(error_message) then
    		table.insert( z.message_tail, { seterror( 'bad_date', {error_message}, true ) } );	-- add this error message
    	end
    
    -- At this point fields may be nil if they weren't specified in the template use.  We can use that fact.
    
    	-- COinS metadata (see <http://ocoins.info/>) for
    	-- automated parsing of citation information.
    	local OCinSoutput = COinS{
    		['Periodical'] = Periodical,
    		['Chapter'] = Chapter,
    		['Title'] = Title,
    		['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(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,
    	};
    
    	if is_set(Periodical) and not is_set(Chapter) and is_set(Title) then
    		Chapter = Title;
    		ChapterLink = TitleLink;
    		TransChapter = TransTitle;
    		Title = '';
    		TitleLink = '';
    		TransTitle = '';
    	end
    --[[ Hide unfinished cite newsgroup code so that long delayed update can take place
    -- special case for cite newsgroup.  Do this after COinS because we are modifying Publishername and ID
    	if 'newsgroup' == config.CitationClass then
    		if is_set (PublisherName) then
    			PublisherName = '[Newsgroup]:&nbsp;' ..  externallink( 'news:' .. PublisherName, PublisherName );
    		end
    	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.
    	if not is_set(Authors) then
    		local Maximum = tonumber( A['DisplayAuthors'] );
    		
    		-- Preserve old-style implicit et al.
    		if not is_set(Maximum) and #a == 9 then 
    			Maximum = 8;
    			table.insert( z.message_tail, { seterror('implict_etal_author', {}, true ) } );
    		elseif not is_set(Maximum) then
    			Maximum = #a + 1;
    		end
    			
    		local control = { 
    			sep = A["AuthorSeparator"] .. " ",
    			namesep = (first_set(A["AuthorNameSeparator"], A["NameSeparator"]) or "") .. " ",
    			format = A["AuthorFormat"],
    			maximum = Maximum,
    			lastauthoramp = LastAuthorAmp
    		};
    		
    		-- If the coauthor field is also used, prevent ampersand and et al. formatting.
    		if is_set(Coauthors) then
    			control.lastauthoramp = nil;
    			control.maximum = #a + 1;
    		end
    		
    		Authors = listpeople(control, a) 
    	end
    
    	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, { seterror('coauthors_missing_author', {}, true) } );	-- emit error message
    	end
    
    	local EditorCount
    	if not is_set(Editors) then
    		local Maximum = tonumber( A['DisplayEditors'] );
    		-- Preserve old-style implicit et al.
    		if not is_set(Maximum) and #e == 4 then 
    			Maximum = 3;
    			table.insert( z.message_tail, { seterror('implict_etal_editor', {}, true) } );
    		elseif not is_set(Maximum) then
    			Maximum = #e + 1;
    		end
    
    		local control = { 
    			sep = A["EditorSeparator"] .. " ",
    			namesep = (first_set(A["EditorNameSeparator"], A["NameSeparator"]) or "") .. " ",
    			format = A['EditorFormat'],
    			maximum = Maximum,
    			lastauthoramp = LastAuthorAmp
    		};
    
    		Editors, EditorCount = listpeople(control, e);
    	else
    		EditorCount = 1;
    	end
    
    	local Cartography = "";
    	local Scale = "";
    	if config.CitationClass == "map" then
    		if not is_set( Authors ) and is_set( PublisherName ) then
    			Authors = PublisherName;
    			PublisherName = "";
    		end
    		Cartography = A['Cartography'];
    		if is_set( Cartography ) then
    			Cartography = sepc .. " " .. wrap( 'cartography', Cartography, use_lowercase );
    		end		
    		Scale = A['Scale'];
    		if is_set( Scale ) then
    			Scale = sepc .. " " .. Scale;
    		end		
    	end
    	
    	if  not is_set(URL) and
    		not is_set(ChapterURL) and
    		not is_set(ArchiveURL) and
    		not is_set(ConferenceURL) and
    		not is_set(TranscriptURL) then
    		
    		-- Test if cite web or cite podcast |url= is missing or empty 
    		if inArray(config.CitationClass, {"web","podcast"}) then	
    			table.insert( z.message_tail, { seterror( 'cite_web_url', {}, true ) } );
    		end
    		
    		-- Test if accessdate is given without giving a URL
    		if is_set(AccessDate) then
    			table.insert( z.message_tail, { seterror( 'accessdate_missing_url', {}, true ) } );
    			AccessDate = '';
    		end
    		
    		-- Test if format is given without giving a URL
    		if is_set(Format) then
    			Format = Format .. seterror( 'format_missing_url' );
    		end
    	end
    	
    	-- Test if citation has no title
    	if  not is_set(Chapter) and
    		not is_set(Title) and
    		not is_set(Periodical) and
    		not is_set(Conference) and
    		not is_set(TransTitle) and
    		not is_set(TransChapter) then
    		table.insert( z.message_tail, { seterror( 'citation_missing_title', {}, true ) } );
    	end
    	
    	Format = is_set(Format) and " (" .. Format .. ")" or "";
    	
    	local OriginalURL = URL
    	DeadURL = DeadURL:lower();
    	if is_set( ArchiveURL ) then
    		if ( DeadURL ~= "no" ) then
    			URL = ArchiveURL
    			URLorigin = A:ORIGIN('ArchiveURL')
    		end
    	end
    	
    	-- Format chapter / article title
    	if is_set(Chapter) and is_set(ChapterLink) then 
    		Chapter = "[[" .. ChapterLink .. "|" .. Chapter .. "]]";
    	end
    	if is_set(Periodical) and is_set(Title) then
    		Chapter = wrap( 'italic-title', Chapter );
    		TransChapter = wrap( 'trans-italic-title', TransChapter );
    	else
    		Chapter = kern_quotes (Chapter);				-- if necessary, separate chapter title's leading and trailing quote marks from Module provided quote marks
    		Chapter = wrap( 'quoted-title', Chapter );
    		TransChapter = wrap( 'trans-quoted-title', TransChapter );
    	end
    	
    	local TransError = ""
    	if is_set(TransChapter) then
    		if not is_set(Chapter) then
    			TransError = " " .. seterror( 'trans_missing_chapter' );
    		else
    			TransChapter = " " .. TransChapter;
    		end
    	end
    	
    	Chapter = Chapter .. TransChapter;
    	
    	if is_set(Chapter) then
    		if not is_set(ChapterLink) then
    			if is_set(ChapterURL) then
    				Chapter = externallink( ChapterURL, Chapter ) .. TransError;
    				if not is_set(URL) then
    					Chapter = Chapter .. Format;
    					Format = "";
    				end
    			elseif is_set(URL) then 
    				Chapter = externallink( URL, Chapter ) .. TransError .. Format;
    				URL = "";
    				Format = "";
    			else
    				Chapter = Chapter .. TransError;
    			end			
    		elseif is_set(ChapterURL) then
    			Chapter = Chapter .. " " .. externallink( ChapterURL, nil, ChapterURLorigin ) .. 
    				TransError;
    		else
    			Chapter = Chapter .. TransError;
    		end
    		Chapter = Chapter .. sepc .. " " -- with end-space
    	elseif is_set(ChapterURL) then
    		Chapter = " " .. externallink( ChapterURL, nil, ChapterURLorigin ) .. sepc .. " ";
    	end		
    	
    	-- Format main title.
    	if is_set(TitleLink) and is_set(Title) then
    		Title = "[[" .. TitleLink .. "|" .. Title .. "]]"
    	end
    	
    	if is_set(Periodical) then
    		Title = kern_quotes (Title);				-- if necessary, separate title's leading and trailing quote marks from Module provided quote marks
    		Title = wrap( 'quoted-title', Title );
    		TransTitle = wrap( 'trans-quoted-title', TransTitle );
    --[[ Hide unfinished cite newsgroup code so that long delayed update can take place
    	elseif inArray(config.CitationClass, {"web","news","pressrelease","conference","podcast","newsgroup"}) and
    ]]	elseif inArray(config.CitationClass, {"web","news","pressrelease","conference","podcast"}) and
    			not is_set(Chapter) then
    		Title = kern_quotes (Title);				-- if necessary, separate title's leading and trailing quote marks from Module provided quote marks
    		Title = wrap( 'quoted-title', Title );
    		TransTitle = wrap( 'trans-quoted-title', TransTitle );
    	else
    		Title = wrap( 'italic-title', Title );
    		TransTitle = wrap( 'trans-italic-title', TransTitle );
    	end
    	
    	TransError = "";
    	if is_set(TransTitle) then
    		if not is_set(Title) then
    			TransError = " " .. seterror( 'trans_missing_title' );
    		else
    			TransTitle = " " .. TransTitle;
    		end
    	end
    	
    	Title = Title .. TransTitle;
    	
    	if is_set(Title) then
    		if not is_set(TitleLink) and is_set(URL) then 
    			Title = externallink( URL, Title ) .. TransError .. Format	   
    			URL = "";
    			Format = "";
    		else
    			Title = Title .. TransError;
    		end
    	end
    	
    	if is_set(Place) then
    		Place = " " .. wrap( 'written', Place, use_lowercase ) .. sepc .. " ";
    	end
    	
    	if is_set(Conference) then
    		if is_set(ConferenceURL) then
    			Conference = externallink( ConferenceURL, Conference );
    		end
    		Conference = sepc .. " " .. Conference
    	elseif is_set(ConferenceURL) then
    		Conference = sepc .. " " .. externallink( ConferenceURL, nil, ConferenceURLorigin );
    	end
    	
    	if not is_set(Position) then
    		local Minutes = A['Minutes'];
    		if is_set(Minutes) then
    			Position = " " .. Minutes .. " " .. cfg.messages['minutes'];
    		else
    			local Time = A['Time'];
    			if is_set(Time) then
    				local TimeCaption = A['TimeCaption']
    				if not is_set(TimeCaption) then
    					TimeCaption = cfg.messages['event'];
    					if sepc ~= '.' then
    						TimeCaption = TimeCaption:lower();
    					end
    				end
    				Position = " " .. TimeCaption .. " " .. Time;
    			end
    		end
    	else
    		Position = " " .. Position;
    		At = '';
    	end
    	
    	if not is_set(Page) then
    		if is_set(Pages) then
    			if is_set(Periodical) and
    				not inArray(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 inArray(config.CitationClass, {"encyclopaedia","web","book","news","podcast"}) then
    			Page = ": " .. Page;
    		else
    			Page = sepc .." " .. PPrefix .. Page;
    		end
    	end
    	
    	At = is_set(At) and (sepc .. " " .. At) or "";
    	Position = is_set(Position) and (sepc .. " " .. Position) or "";
    	if config.CitationClass == 'map' then
    		local Section = A['Section'];
    		local Inset = A['Inset'];
    		if first_set( Pages, Page, At ) ~= nil or sepc ~= '.' then
    			if is_set( Section ) then
    				Section = ", " .. wrap( 'section', Section, true );
    			end
    			if is_set( Inset ) then
    				Inset = ", " .. wrap( 'inset', Inset, true );
    			end
    		else
    			if is_set( Section ) then
    				Section = sepc .. " " .. wrap( 'section', Section, use_lowercase );
    				if is_set( Inset ) then
    					Inset = ", " .. wrap( 'inset', Inset, true );
    				end
    			elseif is_set( Inset ) then
    				Inset = sepc .. " " .. wrap( 'inset', Inset, use_lowercase );
    			end			
    		end			
    		At = At .. Section .. Inset;		
    	end	
    
    	--[[Look in the list of iso639-1 language codes to see if the value provided in the language parameter matches one of them.  If a match is found, 
    	use that value; if not, then use the value that was provided with the language parameter.
    	
    	Categories are assigned in a manner similar to the {{xx icon}} templates - categorizes only mainspace citations and only when the language code is not 'en' (English).
    	]]
    	if is_set (Language) then
    --		local name = mw.language.fetchLanguageName( Language:lower(), "en" );	-- experiment: this seems to return correct ISO 639-1 language names
    		local name = cfg.iso639_1[Language:lower()];		-- get the language name if Language parameter has a valid iso 639-1 code
    		if nil == name then
    			Language=" " .. wrap( 'language', Language );	-- no match, use parameter's value
    		else
    			if 0 == this_page.namespace and 'en' ~= Language:lower() then	--found a match; is this page main / article space and English not the language?
    				Language=" " .. wrap( 'language', name .. '[[Category:Articles with ' .. name .. '-language external links]]' );	-- in main space and not English: categorize
    			else
    				Language=" " .. wrap( 'language', name );	--not in mainspace or language is English so don't categorize
    			end
    		end
    	else
    		Language="";	-- language not specified so make sure this is an empty string;
    	end
    
    	Others = is_set(Others) and (sepc .. " " .. Others) or "";
    
    -- handle type parameter for those CS1 citations that have default values
    
    	if inArray(config.CitationClass, {"AV-media-notes", "DVD-notes", "podcast", "pressrelease", "techreport", "thesis"}) then
    		TitleType = set_titletype (config.CitationClass, TitleType);
    		if is_set(Degree) and "Thesis" == TitleType then	-- special case for cite thesis
    			TitleType = Degree .. " thesis";
    		end
    	end
    
    	if is_set(TitleType) then					-- if type parameter is specified
    		TitleType = " (" .. TitleType .. ")";	-- display it in parentheses
    	end
    
    	TitleNote = is_set(TitleNote) and (sepc .. " " .. TitleNote) or "";
    	Edition = is_set(Edition) and (" " .. wrap( 'edition', Edition )) or "";
    	Issue = is_set(Issue) and (" (" .. Issue .. ")") or "";
    	Series = is_set(Series) and (sepc .. " " .. Series) or "";
    	OrigYear = is_set(OrigYear) and (" [" .. OrigYear .. "]") or "";
    	Agency = is_set(Agency) and (sepc .. " " .. Agency) or "";
    
    	if is_set(Volume) then
    		if ( mw.ustring.len(Volume) > 4 )
    		  then Volume = sepc .." " .. Volume;
    		  else Volume = " <b>" .. hyphentodash(Volume) .. "</b>";
    		end
    	end
    
    --[[ This code commented out while discussion continues until after week of 2014-03-23 live module update;
    	if is_set(Volume) then
    		if ( mw.ustring.len(Volume) > 4 )
    		  then Volume = sepc .. " " .. Volume;
    		  else
    			  Volume = " <b>" .. hyphentodash(Volume) .. "</b>";
    			  if is_set(Series) then Volume = sepc .. Volume;
    			  end
    		end
    	end
    ]]	
    	------------------------------------ totally unrelated data
    	--[[ Loosely mimic {{subscription required}} template; Via parameter identifies a delivery source that is not the publisher; these sources often, but not always, exist
    	behind a registration or paywall.  So here, we've chosen to decouple via from subscription (via has never been part of the registration required template).
    	
    	Subscription implies paywall; Registration does not.  If both are used in a citation, the subscription required link note is displayed. There are no error messages for this condition.
    	]]
    	if is_set(Via) then
    		Via = " " .. wrap( 'via', Via );
    	end
    
    	if is_set(SubscriptionRequired) then
    		SubscriptionRequired = sepc .. " " .. cfg.messages['subscription']; --here when 'via' parameter not used but 'subscription' is
    	elseif is_set(RegistrationRequired) then
    		SubscriptionRequired = sepc .. " " .. cfg.messages['registration']; --here when 'via' and 'subscription' parameters not used but 'registration' is
    	end
    
    	if is_set(AccessDate) then
    		local retrv_text = " " .. cfg.messages['retrieved']
    		if (sepc ~= ".") then retrv_text = retrv_text:lower() end
    		AccessDate = '<span class="reference-accessdate">' .. sepc
    			.. substitute( retrv_text, {AccessDate} ) .. '</span>'
    	end
    	
    	if is_set(ID) then ID = sepc .." ".. ID; end
       	if "thesis" == config.CitationClass and is_set(Docket) then
    		ID = sepc .." Docket ".. Docket .. ID;
    	end
    
    	
    	ID_list = buildidlist( ID_list, {DoiBroken = DoiBroken, ASINTLD = ASINTLD, IgnoreISBN = IgnoreISBN, Embargo=Embargo} );
    
    	if is_set(URL) then
    		URL = " " .. externallink( URL, nil, URLorigin );
    	end
    
    	if is_set(Quote) then
    		if Quote:sub(1,1) == '"' and Quote:sub(-1,-1) == '"' then
    			Quote = Quote:sub(2,-2);
    		end
    		Quote = sepc .." " .. wrap( 'quoted-text', Quote ); 
    		PostScript = "";							-- CS1 does not supply terminal punctuation when |quote= is set
    	end
    	
    	local Archived
    	if is_set(ArchiveURL) then
    		if not is_set(ArchiveDate) then
    			ArchiveDate = seterror('archive_missing_date');
    		end
    		if "no" == DeadURL then
    			local arch_text = cfg.messages['archived'];
    			if sepc ~= "." then arch_text = arch_text:lower() end
    			Archived = sepc .. " " .. substitute( cfg.messages['archived-not-dead'],
    				{ externallink( ArchiveURL, arch_text ), ArchiveDate } );
    			if not is_set(OriginalURL) then
    				Archived = Archived .. " " .. seterror('archive_missing_url');							   
    			end
    		elseif is_set(OriginalURL) then
    			local arch_text = cfg.messages['archived-dead'];
    			if sepc ~= "." then arch_text = arch_text:lower() end
    			Archived = sepc .. " " .. substitute( arch_text,
    				{ externallink( OriginalURL, cfg.messages['original'] ), ArchiveDate } );
    		else
    			local arch_text = cfg.messages['archived-missing'];
    			if sepc ~= "." then arch_text = arch_text:lower() end
    			Archived = sepc .. " " .. substitute( arch_text, 
    				{ seterror('archive_missing_url'), ArchiveDate } );
    		end
    	else
    		Archived = ""
    	end
    	
    	local Lay
    	if is_set(LayURL) then
    		if is_set(LayDate) then LayDate = " (" .. LayDate .. ")" end
    		if is_set(LaySource) then 
    			LaySource = " &ndash; ''" .. safeforitalics(LaySource) .. "''";
    		else
    			LaySource = "";
    		end
    		if sepc == '.' then
    			Lay = sepc .. " " .. externallink( LayURL, cfg.messages['lay summary'] ) .. LaySource .. LayDate
    		else
    			Lay = sepc .. " " .. externallink( LayURL, cfg.messages['lay summary']:lower() ) .. LaySource .. LayDate
    		end			
    	else
    		Lay = "";
    	end
    	
    	if is_set(Transcript) then
    		if is_set(TranscriptURL) then Transcript = externallink( TranscriptURL, Transcript ); end
    	elseif is_set(TranscriptURL) then
    		Transcript = externallink( TranscriptURL, nil, TranscriptURLorigin );
    	end
    	
    	local Publisher;
    	if is_set(Periodical) and
    		not inArray(config.CitationClass, {"encyclopaedia","web","pressrelease","podcast"}) then
    		if is_set(PublisherName) then
    			if is_set(PublicationPlace) then
    				Publisher = PublicationPlace .. ": " .. PublisherName;
    			else
    				Publisher = PublisherName;  
    			end
    		elseif is_set(PublicationPlace) then
    			Publisher= PublicationPlace;
    		else 
    			Publisher = "";
    		end
    		if is_set(PublicationDate) then
    			if is_set(Publisher) then
    				Publisher = Publisher .. ", " .. wrap( 'published', PublicationDate );
    			else
    				Publisher = PublicationDate;
    			end
    		end
    		if is_set(Publisher) then
    			Publisher = " (" .. Publisher .. ")";
    		end
    	else
    		if is_set(PublicationDate) then
    			PublicationDate = " (" .. wrap( 'published', PublicationDate ) .. ")";
    		end
    		if is_set(PublisherName) then
    			if is_set(PublicationPlace) then
    				Publisher = sepc .. " " .. PublicationPlace .. ": " .. PublisherName .. PublicationDate;
    			else
    				Publisher = sepc .. " " .. PublisherName .. PublicationDate;  
    			end			
    		elseif is_set(PublicationPlace) then 
    			Publisher= sepc .. " " .. PublicationPlace .. PublicationDate;
    		else 
    			Publisher = PublicationDate;
    		end
    	end
    	
    	-- Several of the above rely upon detecting this as nil, so do it last.
    	if is_set(Periodical) then
    		if is_set(Title) or is_set(TitleNote) then 
    			Periodical = sepc .. " " .. wrap( 'italic-title', Periodical ) 
    		else 
    			Periodical = wrap( 'italic-title', Periodical )
    		end
    	end
    
    --[[
    Handle the oddity that is cite speech.  This code overrides whatever may be the value assigned to TitleNote (through |department=) and forces it to be " (Speech)" so that
    the annotation directly follows the |title= parameter value in the citation rather than the |event= parameter value (if provided).
    ]]
    	if "speech" == config.CitationClass then				-- cite speech only
    		TitleNote = " (Speech)";							-- annotate the citation
    		if is_set (Periodical) then							-- if Periodical, perhaps because of an included |website= or |journal= parameter 
    			if is_set (Conference) then						-- and if |event= is set
    				Conference = Conference .. sepc .. " ";		-- then add appropriate punctuation to the end of the Conference variable before rendering
    			end
    		end
    	end
    
    	-- Piece all bits together at last.  Here, all should be non-nil.
    	-- We build things this way because it is more efficient in LUA
    	-- not to keep reassigning to the same string variable over and over.
    
    	local tcommon
    	if inArray(config.CitationClass, {"journal","citation"}) and is_set(Periodical) then
    		if is_set(Others) then Others = Others .. sepc .. " " end
    		tcommon = safejoin( {Others, Title, TitleNote, Conference, Periodical, Format, TitleType, Scale, Series, 
    			Language, Cartography, Edition, Publisher, Agency, Volume, Issue}, sepc );
    	else 
    		tcommon = safejoin( {Title, TitleNote, Conference, Periodical, Format, TitleType, Scale, Series, Language, 
    			Volume, Issue, Others, Cartography, Edition, Publisher, Agency}, sepc );
    	end
    	
    	if #ID_list > 0 then
    		ID_list = safejoin( { sepc .. " ",  table.concat( ID_list, sepc .. " " ), ID }, sepc );
    	else
    		ID_list = ID;
    	end
    	
    	local idcommon = safejoin( { ID_list, URL, Archived, AccessDate, Via, SubscriptionRequired, Lay, Quote }, sepc );
    	local text;
    	local pgtext = Position .. Page .. Pages .. At;
    	
    	if is_set(Authors) then
    		if is_set(Coauthors) then
    			Authors = Authors .. A['AuthorSeparator'] .. " " .. Coauthors
    		end
    		if is_set(Date) then
    			Date = " ("..Date..")" .. OrigYear .. sepc .. " "
    		elseif string.sub(Authors,-1,-1) == sepc then
    			Authors = Authors .. " "
    		else
    			Authors = Authors .. sepc .. " "
    		end
    		if is_set(Editors) then
    			local in_text = " ";
    			local post_text = "";
    			if is_set(Chapter) then
    				in_text = in_text .. cfg.messages['in'] .. " "
    			else
    				if EditorCount <= 1 then
    					post_text = ", " .. cfg.messages['editor'];
    				else
    					post_text = ", " .. cfg.messages['editors'];
    				end
    			end 
    			if (sepc ~= '.') then in_text = in_text:lower() end
    			Editors = in_text .. Editors .. post_text;
    			if (string.sub(Editors,-1,-1) == sepc)
    				then Editors = Editors .. " "
    				else Editors = Editors .. sepc .. " "
    			end
    		end
    		text = safejoin( {Authors, Date, Chapter, Place, Editors, tcommon }, sepc );
    		text = safejoin( {text, pgtext, idcommon}, sepc );
    	elseif is_set(Editors) then
    		if is_set(Date) then
    			if EditorCount <= 1 then
    				Editors = Editors .. ", " .. cfg.messages['editor'];
    			else
    				Editors = Editors .. ", " .. cfg.messages['editors'];
    			end
    			Date = " (" .. Date ..")" .. OrigYear .. sepc .. " "
    		else
    			if EditorCount <= 1 then
    				Editors = Editors .. " (" .. cfg.messages['editor'] .. ")" .. sepc .. " "
    			else
    				Editors = Editors .. " (" .. cfg.messages['editors'] .. ")" .. sepc .. " "
    			end
    		end
    		text = safejoin( {Editors, Date, Chapter, Place, tcommon}, sepc );
    		text = safejoin( {text, pgtext, idcommon}, sepc );
    	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
    			text = safejoin( {Chapter, Place, tcommon}, sepc );
    			text = safejoin( {text, pgtext, Date, idcommon}, sepc );
    		else
    			text = safejoin( {Chapter, Place, tcommon, Date}, sepc );
    			text = safejoin( {text, pgtext, idcommon}, sepc );
    		end
    	end
    	
    	if is_set(PostScript) and PostScript ~= sepc then
    		text = safejoin( {text, sepc}, sepc );  --Deals with italics, spaces, etc.
    		text = text:sub(1,-sepc:len()-1);
    --		text = text:sub(1,-2);	--Remove final separator (assumes that sepc is only one character)
    	end	
    	
    	text = safejoin( {text, PostScript}, sepc );
    
    	-- Now enclose the whole thing in a <span/> element
    	local options = {};
    	
    	if is_set(config.CitationClass) and config.CitationClass ~= "citation" then
    		options.class = "citation " .. config.CitationClass;
    	else
    		options.class = "citation";
    	end
    	
    	if is_set(Ref) and Ref:lower() ~= "none" then
    		local id = Ref
    		if ( "harv" == Ref ) then
    			local names = {} --table of last names & year
    			if #a > 0 then
    				for i,v in ipairs(a) do 
    					names[i] = v.last 
    					if i == 4 then break end
    				end
    			elseif #e > 0 then
    				for i,v in ipairs(e) do 
    					names[i] = v.last 
    					if i == 4 then break end				
    				end
    			end
    			names[ #names + 1 ] = first_set(Year, anchor_year);	-- Year first for legacy citations
    			id = anchorid(names)
    		end
    		options.id = id;
    	end
    	
    	if string.len(text:gsub("<span[^>/]*>.-</span>", ""):gsub("%b<>","")) <= 2 then
    		z.error_categories = {};
    		text = seterror('empty_citation');
    		z.message_tail = {};
    	end
    	
    	if is_set(options.id) then 
    		text = '<span id="' .. mw.uri.anchorEncode(options.id) ..'" class="' .. mw.text.nowiki(options.class) .. '">' .. text .. "</span>";
    	else
    		text = '<span class="' .. mw.text.nowiki(options.class) .. '">' .. text .. "</span>";
    	end		
    
    	local empty_span = '<span style="display:none;">&nbsp;</span>';
    	
    	-- Note: Using display: none on then COinS span breaks some clients.
    	local OCinS = '<span title="' .. OCinSoutput .. '" class="Z3988">' .. empty_span .. '</span>';
    	text = text .. OCinS;
    	
    	if #z.message_tail ~= 0 then
    		text = text .. " ";
    		for i,v in ipairs( z.message_tail ) do
    			if is_set(v[1]) then
    				if i == #z.message_tail then
    					text = text .. errorcomment( v[1], v[2] );
    				else
    					text = text .. errorcomment( v[1] .. "; ", v[2] );
    				end
    			end
    		end
    	end
    	
    	no_tracking_cats = no_tracking_cats:lower();
    	if inArray(no_tracking_cats, {"", "no", "false", "n"}) then
    		for _, v in ipairs( z.error_categories ) do
    			text = text .. '[[Category:' .. v ..']]';
    		end
    	end
    	
    	return text
    end
    
    -- This is used by templates such as {{cite book}} to create the actual citation text.
    function z.citation(frame)
    	local pframe = frame:getParent()
    	
    	if nil ~= string.find( frame:getTitle(), 'sandbox', 1, true ) then				-- did the {{#invoke:}} use sandbox version?
    		cfg = mw.loadData( 'Module:Citation/CS1/Configuration/sandbox' );	-- load sandbox versions of Configuration and Whitelist and ...
    		whitelist = mw.loadData( 'Module:Citation/CS1/Whitelist/sandbox' );
    		dates = require('Module:Citation/CS1/Date_validation/sandbox').dates	-- ... sandbox version of date validation code
    	else																	-- otherwise
    		cfg = mw.loadData( 'Module:Citation/CS1/Configuration' );			-- load live versions of Configuration and Whitelist and ...
    		whitelist = mw.loadData( 'Module:Citation/CS1/Whitelist' );
    		dates = require('Module:Citation/CS1/Date_validation').dates		-- ... live version of date validation code
    	end
    	
    	local args = {};
    	local suggestions = {};
    	local error_text, error_state;
    
    	local config = {};
    	for k, v in pairs( frame.args ) do
    		config[k] = v;
    		args[k] = v;	   
    	end	
    
    	for k, v in pairs( pframe.args ) do
    		if v ~= '' then
    			if not validate( k ) then			
    				error_text = "";
    				if type( k ) ~= 'string' then
    					-- Exclude empty numbered parameters
    					if v:match("%S+") ~= nil then
    						error_text, error_state = seterror( 'text_ignored', {v}, true );
    					end
    				elseif validate( k:lower() ) then 
    					error_text, error_state = seterror( 'parameter_ignored_suggest', {k, k:lower()}, true );
    				else
    					if #suggestions == 0 then
    						suggestions = mw.loadData( 'Module:Citation/CS1/Suggestions' );
    					end
    					if suggestions[ k:lower() ] ~= nil then
    						error_text, error_state = seterror( 'parameter_ignored_suggest', {k, suggestions[ k:lower() ]}, true );
    					else
    						error_text, error_state = seterror( 'parameter_ignored', {k}, true );
    					end
    				end				  
    				if error_text ~= '' then
    					table.insert( z.message_tail, {error_text, error_state} );
    				end				
    			end
    			args[k] = v;
    		elseif args[k] ~= nil or (k == 'postscript') then
    			args[k] = v;
    		end		
    	end	
    	
    	return citation0( config, args)
    end
    
    return z