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Module:Citation/CS1






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Permanently protected module

From Wikipedia, the free encyclopedia
 

< Module:Citation


This module and associated sub-modules support the Citation Style 1 and Citation Style 2 citation templates. In general, it is not intended to be called directly, but is called by one of the core CS1 and CS2 templates.

These files comprise the module support for CS1|2 citation templates:

CS1 | CS2 modules
live sandbox diff description
Gold padlock Module:Citation/CS1 Module:Citation/CS1/sandbox [edit] diff Rendering and support functions
Module:Citation/CS1/Configuration Module:Citation/CS1/Configuration/sandbox [edit] diff Translation tables; error and identifier handlers
Module:Citation/CS1/Whitelist Module:Citation/CS1/Whitelist/sandbox [edit] diff List of active and deprecated CS1|2 parameters
Module:Citation/CS1/Date validation Module:Citation/CS1/Date validation/sandbox [edit] diff Date format validation functions
Module:Citation/CS1/Identifiers Module:Citation/CS1/Identifiers/sandbox [edit] diff Functions that support the named identifiers (ISBN, DOI, PMID, etc.)
Module:Citation/CS1/Utilities Module:Citation/CS1/Utilities/sandbox [edit] diff Common functions and tables
Module:Citation/CS1/COinS Module:Citation/CS1/COinS/sandbox [edit] diff Functions that render a CS1|2 template's metadata
Module:Citation/CS1/styles.css Module:Citation/CS1/sandbox/styles.css [edit] diff CSS styles applied to the CS1|2 templates
Silver padlock Module:Citation/CS1/Suggestions Module:Citation/CS1/Suggestions/sandbox [edit] diff List that maps common erroneous parameter names to valid parameter names


Other documentation:

testcases

require ('strict');

--[[--------------------------< F O R W A R D   D E C L A R A T I O N S >--------------------------------------

each of these counts against the Lua upvalue limit

]]

local validation;                -- functions in Module:Citation/CS1/Date_validation

local utilities;                -- functions in Module:Citation/CS1/Utilities
local z = {};                 -- table of tables in Module:Citation/CS1/Utilities

local identifiers;                -- functions and tables in Module:Citation/CS1/Identifiers
local metadata;                 -- functions in Module:Citation/CS1/COinS
local cfg = {};                 -- table of configuration tables that are defined in Module:Citation/CS1/Configuration
local whitelist = {};               -- table of tables listing valid template parameter names; defined in Module:Citation/CS1/Whitelist


--[[------------------< P A G E   S C O P E   V A R I A B L E S >---------------

declare variables here that have page-wide scope that are not brought in from
other modules; that are created here and used here

]]

local added_deprecated_cat;              -- Boolean flag so that the category is added only once
local added_vanc_errs;               -- Boolean flag so we only emit one Vancouver error / category
local added_generic_name_errs;             -- Boolean flag so we only emit one generic name error / category and stop testing names once an error is encountered
local added_numeric_name_errs;             -- Boolean flag so we only emit one numeric name error / category and stop testing names once an error is encountered
local added_numeric_name_maint;             -- Boolean flag so we only emit one numeric name maint category and stop testing names once a category has been emitted
local Frame;                 -- holds the module's frame table
local is_preview_mode;               -- true when article is in preview mode; false when using 'Preview page with this template' (previewing the module)
local is_sandbox;                -- true when using sandbox modules to render citation


--[[--------------------------< F I R S T _ S E T >------------------------------------------------------------

Locates and returns the first set value in a table of values where the order established in the table,
left-to-right (or top-to-bottom), is the order in which the values are evaluated.  Returns nil if none are set.

This version replaces the original 'for _, val in pairs do' and a similar version that used ipairs.  With the pairs
version the order of evaluation could not be guaranteed.  With the ipairs version, a nil value would terminate
the for-loop before it reached the actual end of the list.

]]

local function first_set (list, count)
 local i = 1;
 while i <= count do               -- loop through all items in list
  if utilities.is_set( list[i] ) then
   return list[i];              -- return the first set list member
  end
  i = i + 1;                -- point to next
 end
end


--[[--------------------------< A D D _ V A N C _ E R R O R >----------------------------------------------------

Adds a single Vancouver system error message to the template's output regardless of how many error actually exist.
To prevent duplication, added_vanc_errs is nil until an error message is emitted.

added_vanc_errs is a Boolean declared in page scope variables above

]]

local function add_vanc_error (source, position)
 if added_vanc_errs then return end
  
 added_vanc_errs = true;              -- note that we've added this category
 utilities.set_message ('err_vancouver', {source, position});
end


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

does this thing that purports to be a URI scheme seem to be a valid scheme?  The scheme is checked to see if it
is in agreement with http://tools.ietf.org/html/std66#section-3.1 which says:
 Scheme names consist of a sequence of characters beginning with a
   letter and followed by any combination of letters, digits, plus
   ("+"), period ("."), or hyphen ("-").

returns true if it does, else false

]]

local function is_scheme (scheme)
 return scheme and scheme:match ('^%a[%a%d%+%.%-]*:');      -- true if scheme is set and matches the pattern
end


--[=[-------------------------< I S _ D O M A I N _ N A M E >--------------------------------------------------

Does this thing that purports to be a domain name seem to be a valid domain name?

Syntax defined here: http://tools.ietf.org/html/rfc1034#section-3.5
BNF defined here: https://tools.ietf.org/html/rfc4234
Single character names are generally reserved; see https://tools.ietf.org/html/draft-ietf-dnsind-iana-dns-01#page-15;
 see also [[Single-letter second-level domain]]
list of TLDs: https://www.iana.org/domains/root/db

RFC 952 (modified by RFC 1123) requires the first and last character of a hostname to be a letter or a digit.  Between
the first and last characters the name may use letters, digits, and the hyphen.

Also allowed are IPv4 addresses. IPv6 not supported

domain is expected to be stripped of any path so that the last character in the last character of the TLD.  tld
is two or more alpha characters.  Any preceding '//' (from splitting a URL with a scheme) will be stripped
here.  Perhaps not necessary but retained in case it is necessary for IPv4 dot decimal.

There are several tests:
 the first character of the whole domain name including subdomains must be a letter or a digit
 internationalized domain name (ASCII characters with .xn-- ASCII Compatible Encoding (ACE) prefix xn-- in the TLD) see https://tools.ietf.org/html/rfc3490
 single-letter/digit second-level domains in the .org, .cash, and .today TLDs
 q, x, and z SL domains in the .com TLD
 i and q SL domains in the .net TLD
 single-letter SL domains in the ccTLDs (where the ccTLD is two letters)
 two-character SL domains in gTLDs (where the gTLD is two or more letters)
 three-plus-character SL domains in gTLDs (where the gTLD is two or more letters)
 IPv4 dot-decimal address format; TLD not allowed

returns true if domain appears to be a proper name and TLD or IPv4 address, else false

]=]

local function is_domain_name (domain)
 if not domain then
  return false;               -- if not set, abandon
 end
 
 domain = domain:gsub ('^//', '');           -- strip '//' from domain name if present; done here so we only have to do it once
 
 if not domain:match ('^[%w]') then           -- first character must be letter or digit
  return false;
 end

 if domain:match ('^%a+:') then            -- hack to detect things that look like s:Page:Title where Page: is namespace at Wikisource
  return false;
 end

 local patterns = {               -- patterns that look like URLs
  '%f[%w][%w][%w%-]+[%w]%.%a%a+$',          -- three or more character hostname.hostname or hostname.tld
  '%f[%w][%w][%w%-]+[%w]%.xn%-%-[%w]+$',         -- internationalized domain name with ACE prefix
  '%f[%a][qxz]%.com$',             -- assigned one character .com hostname (x.com times out 2015-12-10)
  '%f[%a][iq]%.net$',              -- assigned one character .net hostname (q.net registered but not active 2015-12-10)
  '%f[%w][%w]%.%a%a$',             -- one character hostname and ccTLD (2 chars)
  '%f[%w][%w][%w]%.%a%a+$',            -- two character hostname and TLD
  '^%d%d?%d?%.%d%d?%d?%.%d%d?%d?%.%d%d?%d?',        -- IPv4 address
  }

 for _, pattern in ipairs (patterns) do          -- loop through the patterns list
  if domain:match (pattern) then
   return true;              -- if a match then we think that this thing that purports to be a URL is a URL
  end
 end

 for _, d in ipairs (cfg.single_letter_2nd_lvl_domains_t) do     -- look for single letter second level domain names for these top level domains
  if domain:match ('%f[%w][%w]%.' .. d) then
   return true
  end
 end
 return false;                -- no matches, we don't know what this thing is
end


--[[--------------------------< I S _ U R L >------------------------------------------------------------------

returns true if the scheme and domain parts of a URL appear to be a valid URL; else false.

This function is the last step in the validation process.  This function is separate because there are cases that
are not covered by split_url(), for example is_parameter_ext_wikilink() which is looking for bracketted external
wikilinks.

]]

local function is_url (scheme, domain)
 if utilities.is_set (scheme) then           -- if scheme is set check it and domain
  return is_scheme (scheme) and is_domain_name (domain);
 else
  return is_domain_name (domain);           -- scheme not set when URL is protocol-relative
 end
end


--[[--------------------------< S P L I T _ U R L >------------------------------------------------------------

Split a URL into a scheme, authority indicator, and domain.

First remove Fully Qualified Domain Name terminator (a dot following TLD) (if any) and any path(/), query(?) or fragment(#).

If protocol-relative URL, return nil scheme and domain else return nil for both scheme and domain.

When not protocol-relative, get scheme, authority indicator, and domain.  If there is an authority indicator (one
or more '/' characters immediately following the scheme's colon), make sure that there are only 2.

Any URL that does not have news: scheme must have authority indicator (//).  TODO: are there other common schemes
like news: that don't use authority indicator?

Strip off any port and path;

]]

local function split_url (url_str)
 local scheme, authority, domain;
 
 url_str = url_str:gsub ('([%a%d])%.?[/%?#].*$', '%1');      -- strip FQDN terminator and path(/), query(?), fragment (#) (the capture prevents false replacement of '//')

 if url_str:match ('^//%S*') then           -- if there is what appears to be a protocol-relative URL
  domain = url_str:match ('^//(%S*)')
 elseif url_str:match ('%S-:/*%S+') then          -- if there is what appears to be a scheme, optional authority indicator, and domain name
  scheme, authority, domain = url_str:match ('(%S-:)(/*)(%S+)');   -- extract the scheme, authority indicator, and domain portions
  if utilities.is_set (authority) then
   authority = authority:gsub ('//', '', 1);       -- replace place 1 pair of '/' with nothing;
   if utilities.is_set(authority) then         -- if anything left (1 or 3+ '/' where authority should be) then
    return scheme;             -- return scheme only making domain nil which will cause an error message
   end
  else
   if not scheme:match ('^news:') then         -- except for news:..., MediaWiki won't link URLs that do not have authority indicator; TODO: a better way to do this test?
    return scheme;             -- return scheme only making domain nil which will cause an error message
   end
  end
  domain = domain:gsub ('(%a):%d+', '%1');        -- strip port number if present
 end
 
 return scheme, domain;
end


--[[--------------------------< L I N K _ P A R A M _ O K >---------------------------------------------------

checks the content of |title-link=, |series-link=, |author-link=, etc. for properly formatted content: no wikilinks, no URLs

Link parameters are to hold the title of a Wikipedia article, so none of the WP:TITLESPECIALCHARACTERS are allowed:
 # < > [ ] | { } _
except the underscore which is used as a space in wiki URLs and # which is used for section links

returns false when the value contains any of these characters.

When there are no illegal characters, this function returns TRUE if value DOES NOT appear to be a valid URL (the
|<param>-link= parameter is ok); else false when value appears to be a valid URL (the |<param>-link= parameter is NOT ok).

]]

local function link_param_ok (value)
 local scheme, domain;
 if value:find ('[<>%[%]|{}]') then           -- if any prohibited characters
  return false;
 end

 scheme, domain = split_url (value);           -- get scheme or nil and domain or nil from URL; 
 return not is_url (scheme, domain);           -- return true if value DOES NOT appear to be a valid URL
end


--[[--------------------------< L I N K _ T I T L E _ O K >---------------------------------------------------

Use link_param_ok() to validate |<param>-link= value and its matching |<title>= value.

|<title>= may be wiki-linked but not when |<param>-link= has a value.  This function emits an error message when
that condition exists

check <link> for inter-language interwiki-link prefix.  prefix must be a MediaWiki-recognized language
code and must begin with a colon.

]]

local function link_title_ok (link, lorig, title, torig)
 local orig;
 if utilities.is_set (link) then            -- don't bother if <param>-link doesn't have a value
  if not link_param_ok (link) then          -- check |<param>-link= markup
   orig = lorig;              -- identify the failing link parameter
  elseif title:find ('%[%[') then           -- check |title= for wikilink markup
   orig = torig;              -- identify the failing |title= parameter
  elseif link:match ('^%a+:') then          -- if the link is what looks like an interwiki
   local prefix = link:match ('^(%a+):'):lower();      -- get the interwiki prefix

   if cfg.inter_wiki_map[prefix] then         -- if prefix is in the map, must have preceding colon
    orig = lorig;             -- flag as error
   end
  end
 end

 if utilities.is_set (orig) then
  link = '';                -- unset
  utilities.set_message ('err_bad_paramlink', orig);      -- URL or wikilink in |title= with |title-link=;
 end
 
 return link;                -- link if ok, empty string else
end


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

Determines whether a URL string appears to be valid.

First we test for space characters.  If any are found, return false.  Then split the URL into scheme and domain
portions, or for protocol-relative (//example.com) URLs, just the domain.  Use is_url() to validate the two
portions of the URL.  If both are valid, or for protocol-relative if domain is valid, return true, else false.

Because it is different from a standard URL, and because this module used external_link() to make external links
that work for standard and news: links, we validate newsgroup names here.  The specification for a newsgroup name
is at https://tools.ietf.org/html/rfc5536#section-3.1.4

]]

local function check_url( url_str )
 if nil == url_str:match ("^%S+$") then          -- if there are any spaces in |url=value it can't be a proper URL
  return false;
 end
 local scheme, domain;

 scheme, domain = split_url (url_str);          -- get scheme or nil and domain or nil from URL;
 
 if 'news:' == scheme then             -- special case for newsgroups
  return domain:match('^[%a%d%+%-_]+%.[%a%d%+%-_%.]*[%a%d%+%-_]$');
 end
 
 return is_url (scheme, domain);            -- return true if value appears to be a valid URL
end


--[=[-------------------------< I S _ P A R A M E T E R _ E X T _ W I K I L I N K >----------------------------

Return true if a parameter value has a string that begins and ends with square brackets [ and ] and the first
non-space characters following the opening bracket appear to be a URL.  The test will also find external wikilinks
that use protocol-relative URLs. Also finds bare URLs.

The frontier pattern prevents a match on interwiki-links which are similar to scheme:path URLs.  The tests that
find bracketed URLs are required because the parameters that call this test (currently |title=, |chapter=, |work=,
and |publisher=) may have wikilinks and there are articles or redirects like '//Hus' so, while uncommon, |title=[[//Hus]]
is possible as might be [[en://Hus]].

]=]

local function is_parameter_ext_wikilink (value)
local scheme, domain;

 if value:match ('%f[%[]%[%a%S*:%S+.*%]') then        -- if ext. wikilink with scheme and domain: [xxxx://yyyyy.zzz]
  scheme, domain = split_url (value:match ('%f[%[]%[(%a%S*:%S+).*%]'));
 elseif value:match ('%f[%[]%[//%S+.*%]') then        -- if protocol-relative ext. wikilink: [//yyyyy.zzz]
  scheme, domain = split_url (value:match ('%f[%[]%[(//%S+).*%]'));
 elseif value:match ('%a%S*:%S+') then          -- if bare URL with scheme; may have leading or trailing plain text
  scheme, domain = split_url (value:match ('(%a%S*:%S+)'));
 elseif value:match ('//%S+') then           -- if protocol-relative bare URL: //yyyyy.zzz; may have leading or trailing plain text
  scheme, domain = split_url (value:match ('(//%S+)'));     -- what is left should be the domain
 else
  return false;               -- didn't find anything that is obviously a URL
 end

 return is_url (scheme, domain);            -- return true if value appears to be a valid URL
end


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

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

]]

local function check_for_url (parameter_list, error_list)
 for k, v in pairs (parameter_list) do          -- for each parameter in the list
  if is_parameter_ext_wikilink (v) then         -- look at the value; if there is a URL add an error message
   table.insert (error_list, utilities.wrap_style ('parameter', k));
  end
 end
end


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

Escape sequences for content that will be used for URL descriptions

]]

local function safe_for_url( str )
 if str:match( "%[%[.-%]%]" ) ~= nil then 
  utilities.set_message ('err_wikilink_in_url', {});
 end
 
 return str:gsub( '[%[%]\n]', { 
  ['['] = '&#91;',
  [']'] = '&#93;',
  ['\n'] = ' ' } );
end


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

Format an external link with error checking

]]

local function external_link (URL, label, source, access)
 local err_msg = '';
 local domain;
 local path;
 local base_url;

 if not utilities.is_set (label) then
  label = URL;
  if utilities.is_set (source) then
   utilities.set_message ('err_bare_url_missing_title', {utilities.wrap_style ('parameter', source)});
  else
   error (cfg.messages["bare_url_no_origin"]);       -- programmer error; valid parameter name does not have matching meta-parameter
  end   
 end
 if not check_url (URL) then
  utilities.set_message ('err_bad_url', {utilities.wrap_style ('parameter', source)});
 end
 
 domain, path = URL:match ('^([/%.%-%+:%a%d]+)([/%?#].*)$');     -- split the URL into scheme plus domain and path
 if path then                -- if there is a path portion
  path = path:gsub ('[%[%]]', {['['] = '%5b', [']'] = '%5d'});   -- replace '[' and ']' with their percent-encoded values
  URL = table.concat ({domain, path});         -- and reassemble
 end

 base_url = table.concat ({ "[", URL, " ", safe_for_url (label), "]" });  -- assemble a wiki-markup URL

 if utilities.is_set (access) then           -- access level (subscription, registration, limited)
  base_url = utilities.substitute (cfg.presentation['ext-link-access-signal'], {cfg.presentation[access].class, cfg.presentation[access].title, base_url}); -- add the appropriate icon
 end

 return base_url;
end


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

Categorize and emit an error message when the citation contains one or more deprecated parameters.  The function includes the
offending parameter name to the error message.  Only one error message is emitted regardless of the number of deprecated
parameters in the citation.

added_deprecated_cat is a Boolean declared in page scope variables above

]]

local function deprecated_parameter(name)
 if not added_deprecated_cat then
  added_deprecated_cat = true;           -- note that we've added this category
  utilities.set_message ('err_deprecated_params', {name});    -- add error message
 end
end


--[=[-------------------------< K E R N _ Q U O T E S >--------------------------------------------------------

Apply kerning to open the space between the quote mark provided by the module and a leading or trailing quote
mark contained in a |title= or |chapter= parameter's value.

This function will positive kern either single or double quotes:
 "'Unkerned title with leading and trailing single quote marks'"
 " 'Kerned title with leading and trailing single quote marks' " (in real life the kerning isn't as wide as this example)
Double single quotes (italic or bold wiki-markup) are not kerned.

Replaces Unicode quote marks in plain text or in the label portion of a [[L|D]] style wikilink with typewriter
quote marks regardless of the need for kerning.  Unicode quote marks are not replaced in simple [[D]] wikilinks.

Call this function for chapter titles, for website titles, etc.; not for book titles.

]=]

local function kern_quotes (str)
 local cap = '';
 local wl_type, label, link;

 wl_type, label, link = utilities.is_wikilink (str);       -- wl_type is: 0, no wl (text in label variable); 1, [[D]]; 2, [[L|D]]
 
 if 1 == wl_type then              -- [[D]] simple wikilink with or without quote marks
  if mw.ustring.match (str, '%[%[[\"“”\'‘’].+[\"“”\'‘’]%]%]') then  -- leading and trailing quote marks
   str = utilities.substitute (cfg.presentation['kern-left'], str);
   str = utilities.substitute (cfg.presentation['kern-right'], str);
  elseif mw.ustring.match (str, '%[%[[\"“”\'‘’].+%]%]') then   -- leading quote marks
   str = utilities.substitute (cfg.presentation['kern-left'], str);
  elseif mw.ustring.match (str, '%[%[.+[\"“”\'‘’]%]%]') then    -- trailing quote marks
   str = utilities.substitute (cfg.presentation['kern-right'], str);
  end

 else                  -- plain text or [[L|D]]; text in label variable
  label = mw.ustring.gsub (label, '[“”]', '\"');       -- replace “” (U+201C & U+201D) with " (typewriter double quote mark)
  label = mw.ustring.gsub (label, '[‘’]', '\'');       -- replace ‘’ (U+2018 & U+2019) with ' (typewriter single quote mark)

  cap = mw.ustring.match (label, "^([\"\'][^\'].+)");      -- match leading double or single quote but not doubled single quotes (italic markup)
  if utilities.is_set (cap) then
   label = utilities.substitute (cfg.presentation['kern-left'], cap);
  end
 
  cap = mw.ustring.match (label, "^(.+[^\'][\"\'])$")      -- match trailing double or single quote but not doubled single quotes (italic markup)
  if utilities.is_set (cap) then
   label = utilities.substitute (cfg.presentation['kern-right'], cap);
  end
  
  if 2 == wl_type then
   str = utilities.make_wikilink (link, label);      -- reassemble the wikilink
  else
   str = label;
  end
 end
 return str;
end


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

|script-title= holds title parameters that are not written in Latin-based scripts: Chinese, Japanese, Arabic, Hebrew, etc. These scripts should
not be italicized and may be written right-to-left.  The value supplied by |script-title= is concatenated onto Title after Title has been wrapped
in italic markup.

Regardless of language, all values provided by |script-title= are wrapped in <bdi>...</bdi> tags to isolate RTL languages from the English left to right.

|script-title= provides a unique feature.  The value in |script-title= may be prefixed with a two-character ISO 639-1 language code and a colon:
 |script-title=ja:*** *** (where * represents a Japanese character)
Spaces between the two-character code and the colon and the colon and the first script character are allowed:
 |script-title=ja : *** ***
 |script-title=ja: *** ***
 |script-title=ja :*** ***
Spaces preceding the prefix are allowed: |script-title = ja:*** ***

The prefix is checked for validity.  If it is a valid ISO 639-1 language code, the lang attribute (lang="ja") is added to the <bdi> tag so that browsers can
know the language the tag contains.  This may help the browser render the script more correctly.  If the prefix is invalid, the lang attribute
is not added.  At this time there is no error message for this condition.

Supports |script-title=, |script-chapter=, |script-<periodical>=

]]

local function format_script_value (script_value, script_param)
 local lang='';                -- initialize to empty string
 local name;
 if script_value:match('^%l%l%l?%s*:') then         -- if first 3 or 4 non-space characters are script language prefix
  lang = script_value:match('^(%l%l%l?)%s*:%s*%S.*');      -- get the language prefix or nil if there is no script
  if not utilities.is_set (lang) then
   utilities.set_message ('err_script_parameter', {script_param, cfg.err_msg_supl['missing title part']});  -- prefix without 'title'; add error message
   return '';               -- script_value was just the prefix so return empty string
  end
                    -- if we get this far we have prefix and script
  name = cfg.lang_tag_remap[lang] or mw.language.fetchLanguageName( lang, cfg.this_wiki_code ); -- get language name so that we can use it to categorize
  if utilities.is_set (name) then           -- is prefix a proper ISO 639-1 language code?
   script_value = script_value:gsub ('^%l+%s*:%s*', '');    -- strip prefix from script
                    -- is prefix one of these language codes?
   if utilities.in_array (lang, cfg.script_lang_codes) then
    utilities.add_prop_cat ('script', {name, lang})
   else
    utilities.set_message ('err_script_parameter', {script_param, cfg.err_msg_supl['unknown language code']}); -- unknown script-language; add error message
   end
   lang = ' lang="' .. lang .. '" ';         -- convert prefix into a lang attribute
  else
   utilities.set_message ('err_script_parameter', {script_param, cfg.err_msg_supl['invalid language code']});  -- invalid language code; add error message
   lang = '';               -- invalid so set lang to empty string
  end
 else
  utilities.set_message ('err_script_parameter', {script_param, cfg.err_msg_supl['missing prefix']});    -- no language code prefix; add error message
 end
 script_value = utilities.substitute (cfg.presentation['bdi'], {lang, script_value}); -- isolate in case script is RTL

 return script_value;
end


--[[--------------------------< S C R I P T _ C O N C A T E N A T E >------------------------------------------

Initially for |title= and |script-title=, this function concatenates those two parameter values after the script
value has been wrapped in <bdi> tags.

]]

local function script_concatenate (title, script, script_param)
 if utilities.is_set (script) then
  script = format_script_value (script, script_param);     -- <bdi> tags, lang attribute, categorization, etc.; returns empty string on error
  if utilities.is_set (script) then
   title = title .. ' ' .. script;          -- concatenate title and script title
  end
 end
 return title;
end


--[[--------------------------< W R A P _ M S G >--------------------------------------------------------------

Applies additional message text to various parameter values. Supplied string is wrapped using a message_list
configuration taking one argument.  Supports lower case text for {{citation}} templates.  Additional text taken
from citation_config.messages - the reason this function is similar to but separate from wrap_style().

]]

local function wrap_msg (key, str, lower)
 if not utilities.is_set ( str ) then
  return "";
 end
 if true == lower then
  local msg;
  msg = cfg.messages[key]:lower();          -- set the message to lower case before 
  return utilities.substitute ( msg, str );        -- including template text
 else
  return utilities.substitute ( cfg.messages[key], str );
 end  
end


--[[----------------< W I K I S O U R C E _ U R L _ M A K E >-------------------

Makes a Wikisource URL from Wikisource interwiki-link.  Returns the URL and appropriate
label; nil else.

str is the value assigned to |chapter= (or aliases) or |title= or |title-link=

]]

local function wikisource_url_make (str)
 local wl_type, D, L;
 local ws_url, ws_label;
 local wikisource_prefix = table.concat ({'https://', cfg.this_wiki_code, '.wikisource.org/wiki/'});

 wl_type, D, L = utilities.is_wikilink (str);        -- wl_type is 0 (not a wikilink), 1 (simple wikilink), 2 (complex wikilink)

 if 0 == wl_type then              -- not a wikilink; might be from |title-link=
  str = D:match ('^[Ww]ikisource:(.+)') or D:match ('^[Ss]:(.+)');  -- article title from interwiki link with long-form or short-form namespace
  if utilities.is_set (str) then
   ws_url = table.concat ({           -- build a Wikisource URL
    wikisource_prefix,            -- prefix
    str,               -- article title
    });
   ws_label = str;              -- label for the URL
  end
 elseif 1 == wl_type then             -- simple wikilink: [[Wikisource:ws article]]
  str = D:match ('^[Ww]ikisource:(.+)') or D:match ('^[Ss]:(.+)');  -- article title from interwiki link with long-form or short-form namespace
  if utilities.is_set (str) then
   ws_url = table.concat ({           -- build a Wikisource URL
    wikisource_prefix,            -- prefix
    str,               -- article title
    });
   ws_label = str;              -- label for the URL
  end
 elseif 2 == wl_type then             -- non-so-simple wikilink: [[Wikisource:ws article|displayed text]] ([[L|D]])
  str = L:match ('^[Ww]ikisource:(.+)') or L:match ('^[Ss]:(.+)');  -- article title from interwiki link with long-form or short-form namespace
  if utilities.is_set (str) then
   ws_label = D;              -- get ws article name from display portion of interwiki link
   ws_url = table.concat ({           -- build a Wikisource URL
    wikisource_prefix,            -- prefix
    str,               -- article title without namespace from link portion of wikilink
    });
  end
 end

 if ws_url then
  ws_url = mw.uri.encode (ws_url, 'WIKI');        -- make a usable URL
  ws_url = ws_url:gsub ('%%23', '#');          -- undo percent-encoding of fragment marker
 end

 return ws_url, ws_label, L or D;           -- return proper URL or nil and a label or nil
end


--[[----------------< F O R M A T _ P E R I O D I C A L >-----------------------

Format the three periodical parameters: |script-<periodical>=, |<periodical>=,
and |trans-<periodical>= into a single Periodical meta-parameter.

]]

local function format_periodical (script_periodical, script_periodical_source, periodical, trans_periodical)

 if not utilities.is_set (periodical) then
  periodical = '';              -- to be safe for concatenation
 else
  periodical = utilities.wrap_style ('italic-title', periodical);   -- style 
 end

 periodical = script_concatenate (periodical, script_periodical, script_periodical_source); -- <bdi> tags, lang attribute, categorization, etc.; must be done after title is wrapped

 if utilities.is_set (trans_periodical) then
  trans_periodical = utilities.wrap_style ('trans-italic-title', trans_periodical);
  if utilities.is_set (periodical) then
   periodical = periodical .. ' ' .. trans_periodical;
  else                 -- here when trans-periodical without periodical or script-periodical
   periodical = trans_periodical;
   utilities.set_message ('err_trans_missing_title', {'periodical'});
  end
 end

 return periodical;
end


--[[------------------< F O R M A T _ C H A P T E R _ T I T L E >---------------

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

]]

local function format_chapter_title (script_chapter, script_chapter_source, chapter, chapter_source, trans_chapter, trans_chapter_source, chapter_url, chapter_url_source, no_quotes, access)
 local ws_url, ws_label, L = wikisource_url_make (chapter);     -- make a wikisource URL and label from a wikisource interwiki link
 if ws_url then
  ws_label = ws_label:gsub ('_', ' ');         -- replace underscore separators with space characters
  chapter = ws_label;
 end

 if not utilities.is_set (chapter) then
  chapter = '';               -- to be safe for concatenation
 else
  if false == no_quotes then
   chapter = kern_quotes (chapter);         -- if necessary, separate chapter title's leading and trailing quote marks from module provided quote marks
   chapter = utilities.wrap_style ('quoted-title', chapter);
  end
 end

 chapter = script_concatenate (chapter, script_chapter, script_chapter_source); -- <bdi> tags, lang attribute, categorization, etc.; must be done after title is wrapped

 if utilities.is_set (chapter_url) then
  chapter = external_link (chapter_url, chapter, chapter_url_source, access); -- adds bare_url_missing_title error if appropriate
 elseif ws_url then
  chapter = external_link (ws_url, chapter .. '&nbsp;', 'ws link in chapter'); -- adds bare_url_missing_title error if appropriate; space char to move icon away from chap text; TODO: better way to do this?
  chapter = utilities.substitute (cfg.presentation['interwiki-icon'], {cfg.presentation['class-wikisource'], L, chapter});    
 end

 if utilities.is_set (trans_chapter) then
  trans_chapter = utilities.wrap_style ('trans-quoted-title', trans_chapter);
  if utilities.is_set (chapter) then
   chapter = chapter .. ' ' .. trans_chapter;
  else                 -- here when trans_chapter without chapter or script-chapter
   chapter = trans_chapter;
   chapter_source = trans_chapter_source:match ('trans%-?(.+)');  -- when no chapter, get matching name from trans-<param>
   utilities.set_message ('err_trans_missing_title', {chapter_source});
  end
 end

 return chapter;
end


--[[----------------< H A S _ I N V I S I B L E _ C H A R S >-------------------

This function searches a parameter's value for non-printable or invisible characters.
The search stops at the first match.

This function will detect the visible replacement character when it is part of the Wikisource.

Detects but ignores nowiki and math stripmarkers.  Also detects other named stripmarkers
(gallery, math, pre, ref) and identifies them with a slightly different error message.
See also coins_cleanup().

Output of this function is an error message that identifies the character or the
Unicode group, or the stripmarker that was detected along with its position (or,
for multi-byte characters, the position of its first byte) in the parameter value.

]]

local function has_invisible_chars (param, v)
 local position = '';              -- position of invisible char or starting position of stripmarker
 local capture;                -- used by stripmarker detection to hold name of the stripmarker
 local stripmarker;               -- boolean set true when a stripmarker is found

 capture = string.match (v, '[%w%p ]*');          -- test for values that are simple ASCII text and bypass other tests if true
 if capture == v then              -- if same there are no Unicode characters
  return;
 end

 for _, invisible_char in ipairs (cfg.invisible_chars) do
  local char_name = invisible_char[1];         -- the character or group name
  local pattern = invisible_char[2];          -- the pattern used to find it
  position, _, capture = mw.ustring.find (v, pattern);     -- see if the parameter value contains characters that match the pattern
  
  if position and (cfg.invisible_defs.zwj == capture) then    -- if we found a zero-width joiner character
   if mw.ustring.find (v, cfg.indic_script) then      -- it's ok if one of the Indic scripts
    position = nil;             -- unset position
   elseif cfg.emoji_t[mw.ustring.codepoint (v, position+1)] then   -- is zwj followed by a character listed in emoji{}?
    position = nil;             -- unset position
   end
  end
  
  if position then
   if 'nowiki' == capture or 'math' == capture or      -- nowiki and math stripmarkers (not an error condition)
    ('templatestyles' == capture and utilities.in_array (param, {'id', 'quote'})) then -- templatestyles stripmarker allowed in these parameters
     stripmarker = true;           -- set a flag
   elseif true == stripmarker and cfg.invisible_defs.del == capture then -- because stripmakers begin and end with the delete char, assume that we've found one end of a stripmarker
    position = nil;             -- unset
   else
    local err_msg;
    if capture and not (cfg.invisible_defs.del == capture or cfg.invisible_defs.zwj == capture) then
     err_msg = capture .. ' ' .. char_name;
    else
     err_msg = char_name .. ' ' .. 'character';
    end

    utilities.set_message ('err_invisible_char', {err_msg, utilities.wrap_style ('parameter', param), position}); -- add error message
    return;               -- and done with this parameter
   end
  end
 end
end


--[[-------------------< A R G U M E N T _ W R A P P E R >----------------------

Argument wrapper.  This function provides support for argument mapping defined
in the configuration file so that multiple names can be transparently aliased to
single internal variable.

]]

local function argument_wrapper ( args )
 local origin = {};
 
 return setmetatable({
  ORIGIN = function ( self, k )
   local dummy = self[k];            -- force the variable to be loaded.
   return origin[k];
  end
 },
 {
  __index = function ( tbl, k )
   if origin[k] ~= nil then
    return nil;
   end
   
   local args, list, v = args, cfg.aliases[k];
   
   if type( list ) == 'table' then
    v, origin[k] = utilities.select_one ( args, list, 'err_redundant_parameters' );
    if origin[k] == nil then
     origin[k] = '';            -- Empty string, not nil
    end
   elseif list ~= nil then
    v, origin[k] = args[list], list;
   else
    -- maybe let through instead of raising an error?
    -- v, origin[k] = args[k], k;
    error( cfg.messages['unknown_argument_map'] .. ': ' .. k);
   end
   
   -- Empty strings, not nil;
   if v == nil then
    v = '';
    origin[k] = '';
   end
   
   tbl = rawset( tbl, k, v );
   return v;
  end,
 });
end


--[[--------------------------< N O W R A P _ D A T E >-------------------------

When date is YYYY-MM-DD format wrap in nowrap span: <span ...>YYYY-MM-DD</span>.
When date is DD MMMM YYYY or is MMMM DD, YYYY then wrap in nowrap span:
<span ...>DD MMMM</span> YYYY or <span ...>MMMM DD,</span> YYYY

DOES NOT yet support MMMM YYYY or any of the date ranges.

]]

local function nowrap_date (date)
 local cap = '';
 local cap2 = '';

 if date:match("^%d%d%d%d%-%d%d%-%d%d$") then
  date = utilities.substitute (cfg.presentation['nowrap1'], date);
 
 elseif date:match("^%a+%s*%d%d?,%s+%d%d%d%d$") or date:match ("^%d%d?%s*%a+%s+%d%d%d%d$") then
  cap, cap2 = string.match (date, "^(.*)%s+(%d%d%d%d)$");
  date = utilities.substitute (cfg.presentation['nowrap2'], {cap, cap2});
 end
 
 return date;
end


--[[--------------------------< S E T _ T I T L E T Y P E >---------------------

This function sets default title types (equivalent to the citation including
|type=<default value>) for those templates that have defaults. Also handles the
special case where it is desirable to omit the title type from the rendered citation
(|type=none).

]]

local function set_titletype (cite_class, title_type)
 if utilities.is_set (title_type) then
  if 'none' == cfg.keywords_xlate[title_type] then
   title_type = '';             -- if |type=none then type parameter not displayed
  end
  return title_type;              -- if |type= has been set to any other value use that value
 end

 return cfg.title_types [cite_class] or '';         -- set template's default title type; else empty string for concatenation
end


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

Joins a sequence of strings together while checking for duplicate separation characters.

]]

local function safe_join( tbl, duplicate_char )
 local f = {};                -- create a function table appropriate to type of 'duplicate character'
  if 1 == #duplicate_char then           -- for single byte ASCII characters use the string library functions
   f.gsub = string.gsub
   f.match = string.match
   f.sub = string.sub
  else                 -- for multi-byte characters use the ustring library functions
   f.gsub = mw.ustring.gsub
   f.match = mw.ustring.match
   f.sub = mw.ustring.sub
  end

 local str = '';                -- the output string
 local comp = '';               -- what does 'comp' mean?
 local end_chr = '';
 local trim;
 for _, value in ipairs( tbl ) do
  if value == nil then value = ''; end
  
  if str == '' then              -- if output string is empty
   str = value;              -- assign value to it (first time through the loop)
  elseif value ~= '' then
   if value:sub(1, 1) == '<' then          -- special case of values enclosed in spans and other markup.
    comp = value:gsub( "%b<>", "" );        -- remove HTML markup (<span>string</span> -> string)
   else
    comp = value;
   end
                    -- typically duplicate_char is sepc
   if f.sub(comp, 1, 1) == duplicate_char then       -- is first character same as duplicate_char? why test first character?
                    --   Because individual string segments often (always?) begin with terminal punct for the
                    --   preceding segment: 'First element' .. 'sepc next element' .. etc.?
    trim = false;
    end_chr = f.sub(str, -1, -1);         -- get the last character of the output string
    -- str = str .. "<HERE(enchr=" .. end_chr .. ")"    -- debug stuff?
    if end_chr == duplicate_char then        -- if same as separator
     str = f.sub(str, 1, -2);         -- remove it
    elseif end_chr == "'" then          -- if it might be wiki-markup
     if f.sub(str, -3, -1) == duplicate_char .. "''" then  -- if last three chars of str are sepc'' 
      str = f.sub(str, 1, -4) .. "''";      -- remove them and add back ''
     elseif  f.sub(str, -5, -1) == duplicate_char .. "]]''" then -- if last five chars of str are sepc]]'' 
      trim = true;           -- why? why do this and next differently from previous?
     elseif f.sub(str, -4, -1) == duplicate_char .. "]''" then -- if last four chars of str are sepc]'' 
      trim = true;           -- same question
     end
    elseif end_chr == "]" then          -- if it might be wiki-markup
     if f.sub(str, -3, -1) == duplicate_char .. "]]" then  -- if last three chars of str are sepc]] wikilink 
      trim = true;
     elseif f.sub(str, -3, -1) == duplicate_char .. '"]' then -- if last three chars of str are sepc"] quoted external link 
      trim = true;
     elseif  f.sub(str, -2, -1) == duplicate_char .. "]" then -- if last two chars of str are sepc] external link
      trim = true;
     elseif f.sub(str, -4, -1) == duplicate_char .. "'']" then -- normal case when |url=something & |title=Title.
      trim = true;
     end
    elseif end_chr == "『 then          -- if last char of output string is a space
     if f.sub(str, -2, -1) == duplicate_char .. 』" then   -- if last two chars of str are <sepc><space>
      str = f.sub(str, 1, -3);        -- remove them both
     end
    end

    if trim then
     if value ~= comp then           -- value does not equal comp when value contains HTML markup
      local dup2 = duplicate_char;
      if f.match(dup2, "%A" ) then dup2 = "%" .. dup2; end -- if duplicate_char not a letter then escape it
      
      value = f.gsub(value, "(%b<>)" .. dup2, "%1", 1 )  -- remove duplicate_char if it follows HTML markup
     else
      value = f.sub(value, 2, -1 );       -- remove duplicate_char when it is first character
     end
    end
   end
   str = str .. value;             -- add it to the output string
  end
 end
 return str;
end


--[[--------------------------< I S _ S U F F I X >-----------------------------

returns true if suffix is properly formed Jr, Sr, or ordinal in the range 1–9.
Puncutation not allowed.

]]

local function is_suffix (suffix)
 if utilities.in_array (suffix, {'Jr', 'Sr', 'Jnr', 'Snr', '1st', '2nd', '3rd'}) or suffix:match ('^%dth$') then
  return true;
 end
 return false;
end


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

For Vancouver style, author/editor names are supposed to be rendered in Latin
(read ASCII) characters.  When a name uses characters that contain diacritical
marks, those characters are to be converted to the corresponding Latin
character. When a name is written using a non-Latin alphabet or logogram, that
name is to be transliterated into Latin characters. The module doesn't do this
so editors may/must.

This test allows |first= and |last= names to contain any of the letters defined
in the four Unicode Latin character sets
 [http://www.unicode.org/charts/PDF/U0000.pdf C0 Controls and Basic Latin] 0041–005A, 0061–007A
 [http://www.unicode.org/charts/PDF/U0080.pdf C1 Controls and Latin-1 Supplement] 00C0–00D6, 00D8–00F6, 00F8–00FF
 [http://www.unicode.org/charts/PDF/U0100.pdf Latin Extended-A] 0100–017F
 [http://www.unicode.org/charts/PDF/U0180.pdf Latin Extended-B] 0180–01BF, 01C4–024F

|lastn= also allowed to contain hyphens, spaces, and apostrophes.
 (http://www.ncbi.nlm.nih.gov/books/NBK7271/box/A35029/)
|firstn= also allowed to contain hyphens, spaces, apostrophes, and periods

This original test:
 if nil == mw.ustring.find (last, "^[A-Za-zÀ-ÖØ-öø-ƿDŽ-ɏ%-%s%']*$")
 or nil == mw.ustring.find (first, "^[A-Za-zÀ-ÖØ-öø-ƿDŽ-ɏ%-%s%'%.]+[2-6%a]*$") then
was written outside of the code editor and pasted here because the code editor
gets confused between character insertion point and cursor position. The test has
been rewritten to use decimal character escape sequence for the individual bytes
of the Unicode characters so that it is not necessary to use an external editor
to maintain this code.

 \195\128-\195\150 – À-Ö (U+00C0–U+00D6 – C0 controls)
 \195\152-\195\182 – Ø-ö (U+00D8-U+00F6 – C0 controls)
 \195\184-\198\191 – ø-ƿ (U+00F8-U+01BF – C0 controls, Latin extended A &B)
 \199\132-\201\143 – DŽ-ɏ (U+01C4-U+024F – Latin extended B)

]]

local function is_good_vanc_name (last, first, suffix, position)
 if not suffix then
  if first:find ('[,%s]') then           -- when there is a space or comma, might be first name/initials + generational suffix
   first = first:match ('(.-)[,%s]+');         -- get name/initials
   suffix = first:match ('[,%s]+(.+)$');        -- get generational suffix
  end
 end
 if utilities.is_set (suffix) then
  if not is_suffix (suffix) then
   add_vanc_error (cfg.err_msg_supl.suffix, position);
   return false;              -- not a name with an appropriate suffix
  end
 end
 if nil == mw.ustring.find (last, "^[A-Za-z\195\128-\195\150\195\152-\195\182\195\184-\198\191\199\132-\201\143\225\184\128-\225\187\191%-%s%']*$") or
  nil == mw.ustring.find (first, "^[A-Za-z\195\128-\195\150\195\152-\195\182\195\184-\198\191\199\132-\201\143\225\184\128-\225\187\191%-%s%'%.]*$") then
   add_vanc_error (cfg.err_msg_supl['non-Latin char'], position);
   return false;              -- not a string of Latin characters; Vancouver requires Romanization
 end;
 return true;
end


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

Attempts to convert names to initials in support of |name-list-style=vanc.  

Names in |firstn= may be separated by spaces or hyphens, or for initials, a period.
See http://www.ncbi.nlm.nih.gov/books/NBK7271/box/A35062/.

Vancouver style requires family rank designations (Jr, II, III, etc.) to be rendered
as Jr, 2nd, 3rd, etc.  See http://www.ncbi.nlm.nih.gov/books/NBK7271/box/A35085/.
This code only accepts and understands generational suffix in the Vancouver format
because Roman numerals look like, and can be mistaken for, initials.

This function uses ustring functions because firstname initials may be any of the
Unicode Latin characters accepted by is_good_vanc_name ().

]]

local function reduce_to_initials (first, position)
 if first:find (',', 1, true) then
  return first;               -- commas not allowed; abandon
 end

 local name, suffix = mw.ustring.match (first, "^(%u+) ([%dJS][%drndth]+)$");

 if not name then               -- if not initials and a suffix
  name = mw.ustring.match (first, "^(%u+)$");        -- is it just initials?
 end

 if name then                -- if first is initials with or without suffix
  if 3 > mw.ustring.len (name) then          -- if one or two initials
   if suffix then              -- if there is a suffix
    if is_suffix (suffix) then          -- is it legitimate?
     return first;            -- one or two initials and a valid suffix so nothing to do
    else
     add_vanc_error (cfg.err_msg_supl.suffix, position);   -- one or two initials with invalid suffix so error message
     return first;            -- and return first unmolested
    end
   else
    return first;             -- one or two initials without suffix; nothing to do
   end
  end
 end                   -- if here then name has 3 or more uppercase letters so treat them as a word

 local initials_t, names_t = {}, {};           -- tables to hold name parts and initials
 local i = 1;                -- counter for number of initials

 names_t = mw.text.split (first, '[%s%-]+');         -- split into a sequence of names and possible suffix

 while names_t[i] do               -- loop through the sequence
  if 1 < i and names_t[i]:match ('[%dJS][%drndth]+%.?$') then    -- if not the first name, and looks like a suffix (may have trailing dot)
   names_t[i] = names_t[i]:gsub ('%.', '');       -- remove terminal dot if present
   if is_suffix (names_t[i]) then          -- if a legitimate suffix
    table.insert (initials_t, ' ' .. names_t[i]);     -- add a separator space, insert at end of initials sequence
    break;               -- and done because suffix must fall at the end of a name
   end                 -- no error message if not a suffix; possibly because of Romanization
  end
  if 3 > i then
   table.insert (initials_t, mw.ustring.sub (names_t[i], 1, 1));  -- insert the initial at end of initials sequence
  end
  i = i + 1;                -- bump the counter
 end
   
 return table.concat (initials_t);           -- Vancouver format does not include spaces.
end


--[[--------------------------< I N T E R W I K I _ P R E F I X E N _ G E T >----------------------------------

extract interwiki prefixen from <value>.  Returns two one or two values:
 false – no prefixen
 nil – prefix exists but not recognized
 project prefix, language prefix – when value has either of:
  :<project>:<language>:<article>
  :<language>:<project>:<article>
 project prefix, nil – when <value> has only a known single-letter prefix
 nil, language prefix – when <value> has only a known language prefix

accepts single-letter project prefixen: 'd' (wikidata), 's' (wikisource), and 'w' (wikipedia) prefixes; at this
writing, the other single-letter prefixen (b (wikibook), c (commons), m (meta), n (wikinews), q (wikiquote), and
v (wikiversity)) are not supported.

]]

local function interwiki_prefixen_get (value, is_link)
 if not value:find (':%l+:') then           -- if no prefix
  return false;               -- abandon; boolean here to distinguish from nil fail returns later
 end

 local prefix_patterns_linked_t = {           -- sequence of valid interwiki and inter project prefixen
  '^%[%[:([dsw]):(%l%l+):',            -- wikilinked; project and language prefixes
  '^%[%[:(%l%l+):([dsw]):',            -- wikilinked; language and project prefixes
  '^%[%[:([dsw]):',              -- wikilinked; project prefix
  '^%[%[:(%l%l+):',              -- wikilinked; language prefix
  }
  
 local prefix_patterns_unlinked_t = {          -- sequence of valid interwiki and inter project prefixen
  '^:([dsw]):(%l%l+):',             -- project and language prefixes
  '^:(%l%l+):([dsw]):',             -- language and project prefixes
  '^:([dsw]):',               -- project prefix
  '^:(%l%l+):',               -- language prefix
  }
 
 local cap1, cap2;
 for _, pattern in ipairs ((is_link and prefix_patterns_linked_t) or prefix_patterns_unlinked_t) do
  cap1, cap2 = value:match (pattern);
  if cap1 then
   break;                -- found a match so stop looking
  end
 end
 
 if cap1 and cap2 then              -- when both then :project:language: or :language:project: (both forms allowed)
  if 1 == #cap1 then              -- length == 1 then :project:language:
   if cfg.inter_wiki_map[cap2] then         -- is language prefix in the interwiki map?
    return cap1, cap2;            -- return interwiki project and interwiki language
   end
  else                 -- here when :language:project:
   if cfg.inter_wiki_map[cap1] then         -- is language prefix in the interwiki map?
    return cap2, cap1;            -- return interwiki project and interwiki language
   end
  end
  return nil;                -- unknown interwiki language
 elseif not (cap1 or cap2) then            -- both are nil?
  return nil;                -- we got something that looks like a project prefix but isn't; return fail
 elseif 1 == #cap1 then              -- here when one capture
  return cap1, nil;              -- length is 1 so return project, nil language
 else                  -- here when one capture and its length it more than 1
  if cfg.inter_wiki_map[cap1] then          -- is language prefix in the interwiki map?
   return nil, cap1;             -- return nil project, language
  end
 end
end


--[[--------------------------< L I S T _ P E O P L E >--------------------------

Formats a list of people (authors, contributors, editors, interviewers, translators) 

names in the list will be linked when
 |<name>-link= has a value
 |<name>-mask- does NOT have a value; masked names are presumed to have been
  rendered previously so should have been linked there

when |<name>-mask=0, the associated name is not rendered

]]

local function list_people (control, people, etal)
 local sep;
 local namesep;
 local format = control.format;
 local maximum = control.maximum;
 local name_list = {};

 if 'vanc' == format then             -- Vancouver-like name styling?
  sep = cfg.presentation['sep_nl_vanc'];         -- name-list separator between names is a comma
  namesep = cfg.presentation['sep_name_vanc'];       -- last/first separator is a space
 else
  sep = cfg.presentation['sep_nl'];          -- name-list separator between names is a semicolon
  namesep = cfg.presentation['sep_name'];         -- last/first separator is <comma><space>
 end
 
 if sep:sub (-1, -1) ~= " " then sep = sep .. " " end
 if utilities.is_set (maximum) and maximum < 1 then return "", 0; end  -- returned 0 is for EditorCount; not used for other names
 
 for i, person in ipairs (people) do
  if utilities.is_set (person.last) then
   local mask = person.mask;
   local one;
   local sep_one = sep;

   if utilities.is_set (maximum) and i > maximum then
    etal = true;
    break;
   end
   
   if mask then
    local n = tonumber (mask);          -- convert to a number if it can be converted; nil else
    if n then
     one = 0 ~= n and string.rep("&mdash;", n) or nil;   -- make a string of (n > 0) mdashes, nil else, to replace name
     person.link = nil;           -- don't create link to name if name is replaces with mdash string or has been set nil
    else
     one = mask;             -- replace name with mask text (must include name-list separator)
     sep_one = " ";            -- modify name-list separator
    end
   else
    one = person.last;            -- get surname
    local first = person.first          -- get given name
    if utilities.is_set (first) then
     if ("vanc" == format) then         -- if Vancouver format
      one = one:gsub ('%.', '');        -- remove periods from surnames (http://www.ncbi.nlm.nih.gov/books/NBK7271/box/A35029/)
      if not person.corporate and is_good_vanc_name (one, first, nil, i) then  -- and name is all Latin characters; corporate authors not tested
       first = reduce_to_initials (first, i);    -- attempt to convert first name(s) to initials
      end
     end
     one = one .. namesep .. first;
    end
   end
   if utilities.is_set (person.link) then
    one = utilities.make_wikilink (person.link, one);    -- link author/editor
   end

   if one then               -- if <one> has a value (name, mdash replacement, or mask text replacement)
    local proj, tag = interwiki_prefixen_get (one, true);   -- get the interwiki prefixen if present

    if 'w' == proj and ('Wikipedia' == mw.site.namespaces.Project['name']) then
     proj = nil;             -- for stuff like :w:de:<article>, :w is unnecessary TODO: maint cat?
    end
    if proj then
     proj = ({['d'] = 'Wikidata', ['s'] = 'Wikisource', ['w'] = 'Wikipedia'})[proj]; -- :w (wikipedia) for linking from a non-wikipedia project
     if proj then 
      one = one .. utilities.wrap_style ('interproj', proj); -- add resized leading space, brackets, static text, language name
      tag = nil;            -- unset; don't do both project and language
     end
    end
    if tag == cfg.this_wiki_code then
     tag = nil;             -- stuff like :en:<article> at en.wiki is pointless TODO: maint cat?
    end
    if tag then
     local lang = cfg.lang_tag_remap[tag] or cfg.mw_languages_by_tag_t[tag];
     if lang then            -- error messaging done in extract_names() where we know parameter names
      one = one .. utilities.wrap_style ('interwiki', lang); -- add resized leading space, brackets, static text, language name
     end
    end

    table.insert (name_list, one);         -- add it to the list of names
    table.insert (name_list, sep_one);        -- add the proper name-list separator
   end
  end
 end

 local count = #name_list / 2;            -- (number of names + number of separators) divided by 2
 if 0 < count then 
  if 1 < count and not etal then
   if 'amp' == format then
    name_list[#name_list-2] = " & ";        -- replace last separator with ampersand text
   elseif 'and' == format then
    if 2 == count then
     name_list[#name_list-2] = cfg.presentation.sep_nl_and;  -- replace last separator with 'and' text
    else
     name_list[#name_list-2] = cfg.presentation.sep_nl_end;  -- replace last separator with '(sep) and' text
    end
   end
  end
  name_list[#name_list] = nil;           -- erase the last separator
 end

 local result = table.concat (name_list);         -- construct list
 if etal and utilities.is_set (result) then         -- etal may be set by |display-authors=etal but we might not have a last-first list
  result = result .. sep .. cfg.messages['et al'];      -- we've got a last-first list and etal so add et al.
 end
 
 return result, count;              -- return name-list string and count of number of names (count used for editor names only)
end


--[[--------------------< M A K E _ C I T E R E F _ I D >-----------------------

Generates a CITEREF anchor ID if we have at least one name or a date.  Otherwise
returns an empty string.

namelist is one of the contributor-, author-, or editor-name lists chosen in that
order.  year is Year or anchor_year.

]]

local function make_citeref_id (namelist, year)
 local names={};       -- a table for the one to four names and year
 for i,v in ipairs (namelist) do   -- loop through the list and take up to the first four last names
  names[i] = v.last
  if i == 4 then break end   -- if four then done
 end
 table.insert (names, year);    -- add the year at the end
 local id = table.concat(names);   -- concatenate names and year for CITEREF id
 if utilities.is_set (id) then   -- if concatenation is not an empty string
  return "CITEREF" .. id;    -- add the CITEREF portion
 else
  return '';       -- return an empty string; no reason to include CITEREF id in this citation
 end
end


--[[--------------------------< C I T E _ C L A S S _A T T R I B U T E _M A K E >------------------------------

construct <cite> tag class attribute for this citation.

<cite_class> – config.CitationClass from calling template
<mode> – value from |mode= parameter

]]

local function cite_class_attribute_make (cite_class, mode)
 local class_t = {};
 table.insert (class_t, 'citation');           -- required for blue highlight
 if 'citation' ~= cite_class then
  table.insert (class_t, cite_class);          -- identify this template for user css
  table.insert (class_t, utilities.is_set (mode) and mode or 'cs1');  -- identify the citation style for user css or javascript
 else
  table.insert (class_t, utilities.is_set (mode) and mode or 'cs2');  -- identify the citation style for user css or javascript
 end
 for _, prop_key in ipairs (z.prop_keys_t) do
  table.insert (class_t, prop_key);          -- identify various properties for user css or javascript
 end

 return table.concat (class_t, ' ');           -- make a big string and done
end


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

Evaluates the content of name parameters (author, editor, etc.) for variations on
the theme of et al.  If found, the et al. is removed, a flag is set to true and
the function returns the modified name and the flag.

This function never sets the flag to false but returns its previous state because
it may have been set by previous passes through this function or by the associated
|display-<names>=etal parameter

]]

local function name_has_etal (name, etal, nocat, param)

 if utilities.is_set (name) then            -- name can be nil in which case just return
  local patterns = cfg.et_al_patterns;          -- get patterns from configuration
  
  for _, pattern in ipairs (patterns) do         -- loop through all of the patterns
   if name:match (pattern) then          -- if this 'et al' pattern is found in name
    name = name:gsub (pattern, '');         -- remove the offending text
    etal = true;             -- set flag (may have been set previously here or by |display-<names>=etal)
    if not nocat then            -- no categorization for |vauthors=
     utilities.set_message ('err_etal', {param});    -- and set an error if not added
    end
   end
  end
 end

 return name, etal;
end


--[[---------------------< N A M E _ I S _ N U M E R I C >----------------------

Add an error message and category when <name> parameter value does not contain letters.  

Add a maintenance category when <name> parameter value has numeric characters mixed with characters that are 
not numeric characters; could be letters and/or punctuation characters.

This function will only emit one error and one maint message for the current template.  Does not emit both error
and maint messages/categories for the same parameter value.

returns nothing

]]

local function name_is_numeric (name, name_alias, list_name)
 local patterns = {
  '^%D+%d',                -- <name> must have digits preceded by other characters
  '^%D*%d+%D+',               -- <name> must have digits followed by other characters
  }

 if not added_numeric_name_errs and mw.ustring.match (name, '^[%A]+$') then -- if we have not already set an error message and <name> does not have any alpha characters
  utilities.set_message ('err_numeric_names', name_alias);    -- add an error message
  added_numeric_name_errs = true;           -- set the flag so we emit only one error message
  return;                 -- when here no point in further testing; abandon
 end

 if not added_numeric_name_maint then          -- if we have already set a maint message
  for _, pattern in ipairs (patterns) do         -- spin through list of patterns
   if mw.ustring.match (name, pattern) then       -- digits preceded or followed by anything but digits; %D+ includes punctuation
    utilities.set_message ('maint_numeric_names', cfg.special_case_translation [list_name]); -- add a maint cat for this template
    added_numeric_name_maint = true;        -- set the flag so we emit only one maint message
    return;               -- when here no point in further testing; abandon
   end
  end
 end
end


--[[-----------------< N A M E _ H A S _ M U L T _ N A M E S >------------------

Evaluates the content of last/surname (authors etc.) parameters for multiple names.
Multiple names are indicated if there is more than one comma or any "unescaped"
semicolons. Escaped semicolons are ones used as part of selected HTML entities.
If the condition is met, the function adds the multiple name maintenance category.

Same test for first except that commas should not appear in given names (MOS:JR says
that the generational suffix does not take a separator character).  Titles, degrees,
postnominals, affiliations, all normally comma separated don't belong in a citation.

<name> – name parameter value
<list_name> – AuthorList, EditorList, etc
<limit> – number of allowed commas; 1 (default) for surnames; 0 for given names

returns nothing

]]

local function name_has_mult_names (name, list_name, limit)
 local _, commas, semicolons, nbsps;
 limit = limit and limit or 1;
 if utilities.is_set (name) then
  _, commas = name:gsub (',', '');          -- count the number of commas
  _, semicolons = name:gsub (';', '');         -- count the number of semicolons
  -- nbsps probably should be its own separate count rather than merged in
  -- some way with semicolons because Lua patterns do not support the
  -- grouping operator that regex does, which means there is no way to add
  -- more entities to escape except by adding more counts with the new
  -- entities
  _, nbsps = name:gsub ('&nbsp;','');          -- count nbsps
  
  -- There is exactly 1 semicolon per &nbsp; entity, so subtract nbsps
  -- from semicolons to 'escape' them. If additional entities are added,
  -- they also can be subtracted.
  if limit < commas or 0 < (semicolons - nbsps) then
   utilities.set_message ('maint_mult_names', cfg.special_case_translation [list_name]); -- add a maint message
  end
 end
end


--[=[-------------------------< I S _ G E N E R I C >----------------------------------------------------------

Compares values assigned to various parameters according to the string provided as <item> in the function call.
<item> can have on of two values:
 'generic_names' – for name-holding parameters: |last=, |first=, |editor-last=, etc
 'generic_titles' – for |title=

There are two types of generic tests.  The 'accept' tests look for a pattern that should not be rejected by the
'reject' test.  For example,
 |author=[[John Smith (author)|Smith, John]]
would be rejected by the 'author' reject test.  But piped wikilinks with 'author' disambiguation should not be
rejected so the 'accept' test prevents that from happening.  Accept tests are always performed before reject
tests.

Each of the 'accept' and 'reject' sequence tables hold tables for en.wiki (['en']) and local.wiki (['local'])
that each can hold a test sequence table  The sequence table holds, at index [1], a test pattern, and, at index
[2], a boolean control value.  The control value tells string.find() or mw.ustring.find() to do plain-text search (true)
or a pattern search (false).  The intent of all this complexity is to make these searches as fast as possible so
that we don't run out of processing time on very large articles.

Returns
 true when a reject test finds the pattern or string
 false when an accept test finds the pattern or string
 nil else

]=]

local function is_generic (item, value, wiki)
 local test_val;
 local str_lower = {               -- use string.lower() for en.wiki (['en']) and use mw.ustring.lower() or local.wiki (['local'])
  ['en'] = string.lower,
  ['local'] = mw.ustring.lower,
  }
 local str_find = {               -- use string.find() for en.wiki (['en']) and use mw.ustring.find() or local.wiki (['local'])
  ['en'] = string.find,
  ['local'] = mw.ustring.find,
  }

 local function test (val, test_t, wiki)          -- local function to do the testing; <wiki> selects lower() and find() functions
  val = test_t[2] and str_lower[wiki](value) or val;      -- when <test_t[2]> set to 'true', plaintext search using lowercase value
  return str_find[wiki] (val, test_t[1], 1, test_t[2]);     -- return nil when not found or matched
 end
  
 local test_types_t = {'accept', 'reject'};         -- test accept patterns first, then reject patterns
 local wikis_t = {'en', 'local'};           -- do tests for each of these keys; en.wiki first, local.wiki second

 for _, test_type in ipairs (test_types_t) do        -- for each test type
  for _, generic_value in pairs (cfg.special_case_translation[item][test_type]) do -- spin through the list of generic value fragments to accept or reject
   for _, wiki in ipairs (wikis_t) do
    if generic_value[wiki] then
     if test (value, generic_value[wiki], wiki) then    -- go do the test
      return ('reject' == test_type);       -- param value rejected, return true; false else
     end
    end
   end
  end
 end
end


--[[--------------------------< N A M E _ I S _ G E N E R I C >------------------------------------------------

calls is_generic() to determine if <name> is a 'generic name' listed in cfg.generic_names; <name_alias> is the
parameter name used in error messaging

]]

local function name_is_generic (name, name_alias)
 if not added_generic_name_errs  and is_generic ('generic_names', name) then
  utilities.set_message ('err_generic_name', name_alias);     -- set an error message
  added_generic_name_errs = true;
 end
end


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

This function calls various name checking functions used to validate the content of the various name-holding parameters.

]]

local function name_checks (last, first, list_name, last_alias, first_alias)
 local accept_name;

 if utilities.is_set (last) then
  last, accept_name = utilities.has_accept_as_written (last);    -- remove accept-this-as-written markup when it wraps all of <last>

  if not accept_name then             -- <last> not wrapped in accept-as-written markup
   name_has_mult_names (last, list_name);        -- check for multiple names in the parameter
   name_is_numeric (last, last_alias, list_name);      -- check for names that have no letters or are a mix of digits and other characters
   name_is_generic (last, last_alias);         -- check for names found in the generic names list
  end
 end

 if utilities.is_set (first) then
  first, accept_name = utilities.has_accept_as_written (first);   -- remove accept-this-as-written markup when it wraps all of <first>

  if not accept_name then             -- <first> not wrapped in accept-as-written markup
   name_has_mult_names (first, list_name, 0);       -- check for multiple names in the parameter; 0 is number of allowed commas in a given name
   name_is_numeric (first, first_alias, list_name);     -- check for names that have no letters or are a mix of digits and other characters
   name_is_generic (first, first_alias);        -- check for names found in the generic names list
  end
  local wl_type, D = utilities.is_wikilink (first);
  if 0 ~= wl_type then
   first = D;
   utilities.set_message ('err_bad_paramlink', first_alias);
  end
 end

 return last, first;               -- done
end


--[[----------------------< E X T R A C T _ N A M E S >-------------------------

Gets name list from the input arguments

Searches through args in sequential order to find |lastn= and |firstn= parameters
(or their aliases), and their matching link and mask parameters. Stops searching
when both |lastn= and |firstn= are not found in args after two sequential attempts:
found |last1=, |last2=, and |last3= but doesn't find |last4= and |last5= then the
search is done.

This function emits an error message when there is a |firstn= without a matching
|lastn=.  When there are 'holes' in the list of last names, |last1= and |last3=
are present but |last2= is missing, an error message is emitted. |lastn= is not
required to have a matching |firstn=.

When an author or editor parameter contains some form of 'et al.', the 'et al.'
is stripped from the parameter and a flag (etal) returned that will cause list_people()
to add the static 'et al.' text from Module:Citation/CS1/Configuration.  This keeps
'et al.' out of the template's metadata.  When this occurs, an error is emitted.

]]

local function extract_names(args, list_name)
 local names = {};               -- table of names
 local last;                 -- individual name components
 local first;
 local link;
 local mask;
 local i = 1;                -- loop counter/indexer
 local n = 1;                -- output table indexer
 local count = 0;               -- used to count the number of times we haven't found a |last= (or alias for authors, |editor-last or alias for editors)
 local etal = false;               -- return value set to true when we find some form of et al. in an author parameter

 local last_alias, first_alias, link_alias;         -- selected parameter aliases used in error messaging
 while true do
  last, last_alias = utilities.select_one ( args, cfg.aliases[list_name .. '-Last'], 'err_redundant_parameters', i );  -- search through args for name components beginning at 1
  first, first_alias = utilities.select_one ( args, cfg.aliases[list_name .. '-First'], 'err_redundant_parameters', i );
  link, link_alias = utilities.select_one ( args, cfg.aliases[list_name .. '-Link'], 'err_redundant_parameters', i );
  mask = utilities.select_one ( args, cfg.aliases[list_name .. '-Mask'], 'err_redundant_parameters', i );
 
  if last then               -- error check |lastn= alias for unknown interwiki link prefix; done here because this is where we have the parameter name
   local project, language = interwiki_prefixen_get (last, true);  -- true because we expect interwiki links in |lastn= to be wikilinked
   if nil == project and nil == language then       -- when both are nil
    utilities.set_message ('err_bad_paramlink', last_alias);  -- not known, emit an error message -- TODO: err_bad_interwiki?
    last = utilities.remove_wiki_link (last);      -- remove wikilink markup; show display value only
   end
  end
  
  if link then               -- error check |linkn= alias for unknown interwiki link prefix
   local project, language = interwiki_prefixen_get (link, false);  -- false because wiki links in |author-linkn= is an error
   if nil == project and nil == language then       -- when both are nil
    utilities.set_message ('err_bad_paramlink', link_alias);  -- not known, emit an error message -- TODO: err_bad_interwiki?
    link = nil;              -- unset so we don't link
    link_alias = nil;
   end
  end
  
  last, etal = name_has_etal (last, etal, false, last_alias);    -- find and remove variations on et al.
  first, etal = name_has_etal (first, etal, false, first_alias);   -- find and remove variations on et al.
  last, first = name_checks (last, first, list_name, last_alias, first_alias);      -- multiple names, extraneous annotation, etc. checks

  if first and not last then            -- if there is a firstn without a matching lastn
   local alias = first_alias:find ('given', 1, true) and 'given' or 'first'; -- get first or given form of the alias
   utilities.set_message ('err_first_missing_last', {
    first_alias,             -- param name of alias missing its mate
    first_alias:gsub (alias, {['first'] = 'last', ['given'] = 'surname'}), -- make param name appropriate to the alias form
    });                -- add this error message
  elseif not first and not last then          -- if both firstn and lastn aren't found, are we done?
   count = count + 1;             -- number of times we haven't found last and first
   if 2 <= count then             -- two missing names and we give up
    break;               -- normal exit or there is a two-name hole in the list; can't tell which
   end
  else                 -- we have last with or without a first
   local result;
   link = link_title_ok (link, link_alias, last, last_alias);   -- check for improper wiki-markup

   if first then
    link = link_title_ok (link, link_alias, first, first_alias); -- check for improper wiki-markup
   end

   names[n] = {last = last, first = first, link = link, mask = mask, corporate = false}; -- add this name to our names list (corporate for |vauthors= only)
   n = n + 1;               -- point to next location in the names table
   if 1 == count then             -- if the previous name was missing
    utilities.set_message ('err_missing_name', {list_name:match ("(%w+)List"):lower(), i - 1}); -- add this error message
   end
   count = 0;               -- reset the counter, we're looking for two consecutive missing names
  end
  i = i + 1;                -- point to next args location
 end
 
 return names, etal;               -- all done, return our list of names and the etal flag
end


--[[--------------------------< N A M E _ T A G _ G E T >------------------------------------------------------

attempt to decode |language=<lang_param> and return language name and matching tag; nil else.

This function looks for:
 <lang_param> as a tag in cfg.lang_tag_remap{}
 <lang_param> as a name in cfg.lang_name_remap{}
 
 <lang_param> as a name in cfg.mw_languages_by_name_t
 <lang_param> as a tag in cfg.mw_languages_by_tag_t
when those fail, presume that <lang_param> is an IETF-like tag that MediaWiki does not recognize.  Strip all
script, region, variant, whatever subtags from <lang_param> to leave just a two or three character language tag
and look for the new <lang_param> in cfg.mw_languages_by_tag_t{}

on success, returns name (in properly capitalized form) and matching tag (in lowercase); on failure returns nil

]]

local function name_tag_get (lang_param)
 local lang_param_lc = mw.ustring.lower (lang_param);      -- use lowercase as an index into the various tables
 local name;
 local tag;

 name = cfg.lang_tag_remap[lang_param_lc];         -- assume <lang_param_lc> is a tag; attempt to get remapped language name 
 if name then                -- when <name>, <lang_param> is a tag for a remapped language name
  if cfg.lang_name_remap[name:lower()][2] ~= lang_param_lc then
   utilities.set_message ('maint_unknown_lang');      -- add maint category if not already added
   return name, cfg.lang_name_remap[name:lower()][2];     -- so return name and tag from lang_name_remap[name]; special case to xlate sr-ec and sr-el to sr-cyrl and sr-latn
  end
  return name, lang_param_lc;            -- so return <name> from remap and <lang_param_lc>
 end

 tag = lang_param_lc:match ('^(%a%a%a?)%-.*');        -- still assuming that <lang_param_lc> is a tag; strip script, region, variant subtags
 name = cfg.lang_tag_remap[tag];            -- attempt to get remapped language name with language subtag only
 if name then                -- when <name>, <tag> is a tag for a remapped language name
  return name, tag;              -- so return <name> from remap and <tag>
 end

 if cfg.lang_name_remap[lang_param_lc] then         -- not a remapped tag, assume <lang_param_lc> is a name; attempt to get remapped language tag 
  return cfg.lang_name_remap[lang_param_lc][1], cfg.lang_name_remap[lang_param_lc][2]; -- for this <lang_param_lc>, return a (possibly) new name and appropriate tag
 end

 name = cfg.mw_languages_by_tag_t[lang_param_lc];       -- assume that <lang_param_lc> is a tag; attempt to get its matching language name
 
 if name then
  return name, lang_param_lc;            -- <lang_param_lc> is a tag so return it and <name>
 end
 
 tag = cfg.mw_languages_by_name_t[lang_param_lc];       -- assume that <lang_param_lc> is a language name; attempt to get its matching tag
 
 if tag then
  return cfg.mw_languages_by_tag_t[tag], tag;        -- <lang_param_lc> is a name so return the name from the table and <tag>
 end

 tag = lang_param_lc:match ('^(%a%a%a?)%-.*');        -- is <lang_param_lc> an IETF-like tag that MediaWiki doesn't recognize? <tag> gets the language subtag; nil else

 if tag then
  name = cfg.mw_languages_by_tag_t[tag];         -- attempt to get a language name using the shortened <tag>
  if name then
   return name, tag;             -- <lang_param_lc> is an unrecognized IETF-like tag so return <name> and language subtag
  end
 end
end


--[[-------------------< L A N G U A G E _ P A R A M E T E R >------------------

Gets language name from a provided two- or three-character ISO 639 code.  If a code
is recognized by MediaWiki, use the returned name; if not, then use the value that
was provided with the language parameter.

When |language= contains a recognized language (either code or name), the page is
assigned to the category for that code: Category:Norwegian-language sources (no).
For valid three-character code languages, the page is assigned to the single category
for '639-2' codes: Category:CS1 ISO 639-2 language sources.

Languages that are the same as the local wiki are not categorized.  MediaWiki does
not recognize three-character equivalents of two-character codes: code 'ar' is
recognized but code 'ara' is not.

This function supports multiple languages in the form |language=nb, French, th
where the language names or codes are separated from each other by commas with
optional space characters.

]]

local function language_parameter (lang)
 local tag;                 -- some form of IETF-like language tag; language subtag with optional region, sript, vatiant, etc subtags
 local lang_subtag;               -- ve populates |language= with mostly unecessary region subtags the MediaWiki does not recognize; this is the base language subtag
 local name;                 -- the language name
 local language_list = {};             -- table of language names to be rendered
 local names_t = {};               -- table made from the value assigned to |language=

 local this_wiki_name = mw.language.fetchLanguageName (cfg.this_wiki_code, cfg.this_wiki_code); -- get this wiki's language name

 names_t = mw.text.split (lang, '%s*,%s*');         -- names should be a comma separated list

 for _, lang in ipairs (names_t) do           -- reuse lang here because we don't yet know if lang is a language name or a language tag
  name, tag = name_tag_get (lang);          -- attempt to get name/tag pair for <lang>; <name> has proper capitalization; <tag> is lowercase

  if utilities.is_set (tag) then
   lang_subtag = tag:gsub ('^(%a%a%a?)%-.*', '%1');     -- for categorization, strip any IETF-like tags from language tag

   if cfg.this_wiki_code ~= lang_subtag then       -- when the language is not the same as this wiki's language
    if 2 == lang_subtag:len() then         -- and is a two-character tag
     utilities.add_prop_cat ('foreign-lang-source', {name, tag}, lang_subtag);  -- categorize it; tag appended to allow for multiple language categorization
    else               -- or is a recognized language (but has a three-character tag)
     utilities.add_prop_cat ('foreign-lang-source-2', {lang_subtag}, lang_subtag);   -- categorize it differently TODO: support multiple three-character tag categories per cs1|2 template?
    end
   elseif cfg.local_lang_cat_enable then        -- when the language and this wiki's language are the same and categorization is enabled
    utilities.add_prop_cat ('local-lang-source', {name, lang_subtag});  -- categorize it
   end
  else
   name = lang;              -- return whatever <lang> has so that we show something
   utilities.set_message ('maint_unknown_lang');      -- add maint category if not already added
  end
  
  table.insert (language_list, name);
  name = '';                -- so we can reuse it
 end
 
 name = utilities.make_sep_list (#language_list, language_list);
 if (1 == #language_list) and (lang_subtag == cfg.this_wiki_code) then  -- when only one language, find lang name in this wiki lang name; for |language=en-us, 'English' in 'American English'
  return '';                -- if one language and that language is this wiki's return an empty string (no annotation)
 end
 return (" " .. wrap_msg ('language', name));        -- otherwise wrap with '(in ...)'
 --[[ TODO: should only return blank or name rather than full list
 so we can clean up the bunched parenthetical elements Language, Type, Format
 ]]
end


--[[-----------------------< S E T _ C S _ S T Y L E >--------------------------

Gets the default CS style configuration for the given mode.
Returns default separator and either postscript as passed in or the default.
In CS1, the default postscript and separator are '.'.
In CS2, the default postscript is the empty string and the default separator is ','.

]]

local function set_cs_style (postscript, mode)
 if utilities.is_set(postscript) then
  -- emit a maintenance message if user postscript is the default cs1 postscript
  -- we catch the opposite case for cs2 in set_style
  if mode == 'cs1' and postscript == cfg.presentation['ps_' .. mode] then
   utilities.set_message ('maint_postscript');
  end
 else
  postscript = cfg.presentation['ps_' .. mode];
 end
 return cfg.presentation['sep_' .. mode], postscript;
end


--[[--------------------------< S E T _ S T Y L E >-----------------------------

Sets the separator and postscript styles. Checks the |mode= first and the
#invoke CitationClass second. Removes the postscript if postscript == none.

]]

local function set_style (mode, postscript, cite_class)
 local sep;
 if 'cs2' == mode then
  sep, postscript = set_cs_style (postscript, 'cs2');
 elseif 'cs1' == mode then
  sep, postscript = set_cs_style (postscript, 'cs1');
 elseif 'citation' == cite_class then
  sep, postscript = set_cs_style (postscript, 'cs2');
 else
  sep, postscript = set_cs_style (postscript, 'cs1');
 end

 if cfg.keywords_xlate[postscript:lower()] == 'none' then
  -- emit a maintenance message if user postscript is the default cs2 postscript
  -- we catch the opposite case for cs1 in set_cs_style
  if 'cs2' == mode or ('cs1' ~= mode and 'citation' == cite_class) then -- {{citation |title=Title |mode=cs1 |postscript=none}} should not emit maint message
   utilities.set_message ('maint_postscript');
  end
  postscript = '';
 end
 
 return sep, postscript
end


--[=[-------------------------< I S _ P D F >-----------------------------------

Determines if a URL has the file extension that is one of the PDF file extensions
used by [[MediaWiki:Common.css]] when applying the PDF icon to external links.

returns true if file extension is one of the recognized extensions, else false

]=]

local function is_pdf (url)
 return url:match ('%.pdf$') or url:match ('%.PDF$') or
  url:match ('%.pdf[%?#]') or url:match ('%.PDF[%?#]') or
  url:match ('%.PDF&#035') or url:match ('%.pdf&#035');
end


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

Applies CSS style to |format=, |chapter-format=, etc.  Also emits an error message
if the format parameter does not have a matching URL parameter.  If the format parameter
is not set and the URL contains a file extension that is recognized as a PDF document
by MediaWiki's commons.css, this code will set the format parameter to (PDF) with
the appropriate styling.

]]

local function style_format (format, url, fmt_param, url_param)
 if utilities.is_set (format) then
  format = utilities.wrap_style ('format', format);      -- add leading space, parentheses, resize
  if not utilities.is_set (url) then
   utilities.set_message ('err_format_missing_url', {fmt_param, url_param}); -- add an error message
  end
 elseif is_pdf (url) then             -- format is not set so if URL is a PDF file then
  format = utilities.wrap_style ('format', 'PDF');      -- set format to PDF
 else
  format = '';               -- empty string for concatenation
 end
 return format;
end


--[[---------------------< G E T _ D I S P L A Y _ N A M E S >------------------

Returns a number that defines the number of names displayed for author and editor
name lists and a Boolean flag to indicate when et al. should be appended to the name list.

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

When the value assigned to |display-xxxxors= is the keyword 'etal', return a number
that is one greater than the number of authors in the list and set the 'etal' flag true.
This will cause the list_people() to display all of the names in the name list followed by 'et al.'

In all other cases, returns nil and the previous state of the 'etal' flag.

inputs:
 max: A['DisplayAuthors'] or A['DisplayEditors'], etc; a number or some flavor of etal
 count: #a or #e
 list_name: 'authors' or 'editors'
 etal: author_etal or editor_etal

This function sets an error message when |display-xxxxors= value greater than or equal to number of names but
not when <max> comes from {{cs1 config}} global settings.  When using global settings, <param> is set to the
keyword 'cs1 config' which is used to supress the normal error.  Error is suppressed because it is to be expected
that some citations in an article will have the same or fewer names that the limit specified in {{cs1 config}}.

]]

local function get_display_names (max, count, list_name, etal, param)
 if utilities.is_set (max) then
  if 'etal' == max:lower():gsub("[ '%.]", '') then      -- the :gsub() portion makes 'etal' from a variety of 'et al.' spellings and stylings
   max = count + 1;             -- number of authors + 1 so display all author name plus et al.
   etal = true;              -- overrides value set by extract_names()
  elseif max:match ('^%d+$') then           -- if is a string of numbers
   max = tonumber (max);            -- make it a number
   if (max >= count) and ('cs1 config' ~= param) then     -- error when local |display-xxxxors= value greater than or equal to number of names; not an error when using global setting
    utilities.set_message ('err_disp_name', {param, max});   -- add error message
    max = nil;
   end
  else                 -- not a valid keyword or number
   utilities.set_message ('err_disp_name', {param, max});    -- add error message
   max = nil;               -- unset; as if |display-xxxxors= had not been set
  end
 end
 
 return max, etal;
end


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

Adds error if |page=, |pages=, |quote-page=, |quote-pages= has what appears to be
some form of p. or pp. abbreviation in the first characters of the parameter content.

check page for extraneous p, p., pp, pp., pg, pg. at start of parameter value:
 good pattern: '^P[^%.P%l]' matches when page begins PX or P# but not Px
        where x and X are letters and # is a digit
 bad pattern:  '^[Pp][PpGg]' matches when page begins pp, pP, Pp, PP, pg, pG, Pg, PG

]]

local function extra_text_in_page_check (val, name)
 if not val:match (cfg.vol_iss_pg_patterns.good_ppattern) then
  for _, pattern in ipairs (cfg.vol_iss_pg_patterns.bad_ppatterns) do  -- spin through the selected sequence table of patterns
   if val:match (pattern) then           -- when a match, error so
    utilities.set_message ('err_extra_text_pages', name);    -- add error message
    return;               -- and done
   end
  end
 end  
end


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

Adds error if |volume= or |issue= has what appears to be some form of redundant 'type' indicator.  Applies to
both; this function looks for issue text in both |issue= and |volume= and looks for volume-like text in |voluem=
and |issue=.

For |volume=:
 'V.', or 'Vol.' (with or without the dot) abbreviations or 'Volume' in the first characters of the parameter
 content (all case insensitive). 'V' and 'v' (without the dot) are presumed to be roman numerals so
 are allowed.

For |issue=:
 'No.', 'I.', 'Iss.' (with or without the dot) abbreviations, or 'Issue' in the first characters of the
 parameter content (all case insensitive); numero styling: 'n°' with degree sign U+00B0, and № precomposed
 numero sign U+2116.
 
Single character values ('v', 'i', 'n') allowed when not followed by separator character ('.', ':', '=', or
whitespace character) – param values are trimmed of whitespace by MediaWiki before delivered to the module.
 
<val> is |volume= or |issue= parameter value
<name> is |volume= or |issue= parameter name for error message
<selector> is 'v' for |volume=, 'i' for |issue=

sets error message on failure; returns nothing

]]

local function extra_text_in_vol_iss_check (val, name, selector)
 if not utilities.is_set (val) then
  return;
 end
 
 local handler = 'v' == selector and 'err_extra_text_volume' or 'err_extra_text_issue';
 val = val:lower();               -- force parameter value to lower case

 for _, pattern in ipairs (cfg.vol_iss_pg_patterns.vi_patterns_t) do   -- spin through the sequence table of patterns
  if val:match (pattern) then            -- when a match, error so
   utilities.set_message (handler, name);        -- add error message
   return;                -- and done
  end
 end
end


--[=[-------------------------< G E T _ V _ N A M E _ T A B L E >----------------------------------------------

split apart a |vauthors= or |veditors= parameter.  This function allows for corporate names, wrapped in doubled
parentheses to also have commas; in the old version of the code, the doubled parentheses were included in the
rendered citation and in the metadata.  Individual author names may be wikilinked

 |vauthors=Jones AB, [[E. B. White|White EB]], ((Black, Brown, and Co.))

]=]

local function get_v_name_table (vparam, output_table, output_link_table)
 local name_table = mw.text.split(vparam, "%s*,%s*");      -- names are separated by commas
 local wl_type, label, link;             -- wl_type not used here; just a placeholder
 
 local i = 1;
 
 while name_table[i] do
  if name_table[i]:match ('^%(%(.*[^%)][^%)]$') then      -- first segment of corporate with one or more commas; this segment has the opening doubled parentheses
   local name = name_table[i];
   i = i + 1;               -- bump indexer to next segment
   while name_table[i] do
    name = name .. ', ' .. name_table[i];       -- concatenate with previous segments
    if name_table[i]:match ('^.*%)%)$') then      -- if this table member has the closing doubled parentheses
     break;              -- and done reassembling so
    end
    i = i + 1;              -- bump indexer
   end
   table.insert (output_table, name);         -- and add corporate name to the output table
   table.insert (output_link_table, '');        -- no wikilink
  else
   wl_type, label, link = utilities.is_wikilink (name_table[i]);  -- wl_type is: 0, no wl (text in label variable); 1, [[D]]; 2, [[L|D]]
   table.insert (output_table, label);         -- add this name
   if 1 == wl_type then
    table.insert (output_link_table, label);      -- simple wikilink [[D]]
   else
    table.insert (output_link_table, link);       -- no wikilink or [[L|D]]; add this link if there is one, else empty string
   end
  end
  i = i + 1;
 end 
 return output_table;
end


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

This function extracts author / editor names from |vauthors= or |veditors= and finds matching |xxxxor-maskn= and
|xxxxor-linkn= in args.  It then returns a table of assembled names just as extract_names() does.

Author / editor names in |vauthors= or |veditors= must be in Vancouver system style. Corporate or institutional names
may sometimes be required and because such names will often fail the is_good_vanc_name() and other format compliance
tests, are wrapped in doubled parentheses ((corporate name)) to suppress the format tests.

Supports generational suffixes Jr, 2nd, 3rd, 4th–6th.

This function sets the Vancouver error when a required comma is missing and when there is a space between an author's initials.

]]

local function parse_vauthors_veditors (args, vparam, list_name)
 local names = {};               -- table of names assembled from |vauthors=, |author-maskn=, |author-linkn=
 local v_name_table = {};
 local v_link_table = {};             -- when name is wikilinked, targets go in this table
 local etal = false;               -- return value set to true when we find some form of et al. vauthors parameter
 local last, first, link, mask, suffix;
 local corporate = false;

 vparam, etal = name_has_etal (vparam, etal, true);       -- find and remove variations on et al. do not categorize (do it here because et al. might have a period)
 v_name_table = get_v_name_table (vparam, v_name_table, v_link_table);  -- names are separated by commas

 for i, v_name in ipairs(v_name_table) do
  first = '';                -- set to empty string for concatenation and because it may have been set for previous author/editor
  local accept_name;
  v_name, accept_name = utilities.has_accept_as_written (v_name);   -- remove accept-this-as-written markup when it wraps all of <v_name>

  if accept_name then
   last = v_name;
   corporate = true;             -- flag used in list_people()
  elseif string.find(v_name, "%s") then
   if v_name:find('[;%.]') then          -- look for commonly occurring punctuation characters; 
    add_vanc_error (cfg.err_msg_supl.punctuation, i);
   end
   local lastfirstTable = {}
   lastfirstTable = mw.text.split(v_name, "%s+")
   first = table.remove(lastfirstTable);        -- removes and returns value of last element in table which should be initials or generational suffix

   if not mw.ustring.match (first, '^%u+$') then      -- mw.ustring here so that later we will catch non-Latin characters
    suffix = first;             -- not initials so assume that whatever we got is a generational suffix
    first = table.remove(lastfirstTable);       -- get what should be the initials from the table
   end
   last = table.concat(lastfirstTable, ' ')       -- returns a string that is the concatenation of all other names that are not initials and generational suffix
   if not utilities.is_set (last) then
    first = '';              -- unset
    last = v_name;             -- last empty because something wrong with first
    add_vanc_error (cfg.err_msg_supl.name, i);
   end
   if mw.ustring.match (last, '%a+%s+%u+%s+%a+') then
    add_vanc_error (cfg.err_msg_supl['missing comma'], i);   -- matches last II last; the case when a comma is missing
   end
   if mw.ustring.match (v_name, ' %u %u$') then      -- this test is in the wrong place TODO: move or replace with a more appropriate test
    add_vanc_error (cfg.err_msg_supl.initials, i);     -- matches a space between two initials
   end
  else
   last = v_name;              -- last name or single corporate name?  Doesn't support multiword corporate names? do we need this?
  end
  
  if utilities.is_set (first) then
   if not mw.ustring.match (first, "^%u?%u$") then      -- first shall contain one or two upper-case letters, nothing else
    add_vanc_error (cfg.err_msg_supl.initials, i);     -- too many initials; mixed case initials (which may be ok Romanization); hyphenated initials
   end
   is_good_vanc_name (last, first, suffix, i);       -- check first and last before restoring the suffix which may have a non-Latin digit
   if utilities.is_set (suffix) then
    first = first .. ' ' .. suffix;         -- if there was a suffix concatenate with the initials
    suffix = '';             -- unset so we don't add this suffix to all subsequent names
   end
  else
   if not corporate then
    is_good_vanc_name (last, '', nil, i);
   end
  end

  link = utilities.select_one ( args, cfg.aliases[list_name .. '-Link'], 'err_redundant_parameters', i ) or v_link_table[i];
  mask = utilities.select_one ( args, cfg.aliases[list_name .. '-Mask'], 'err_redundant_parameters', i );
  names[i] = {last = last, first = first, link = link, mask = mask, corporate = corporate};  -- add this assembled name to our names list
 end
 return names, etal;               -- all done, return our list of names
end


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

Select one of |authors=, |authorn= / |lastn / firstn=, or |vauthors= as the source of the author name list or
select one of |editorn= / editor-lastn= / |editor-firstn= or |veditors= as the source of the editor name list.

Only one of these appropriate three will be used.  The hierarchy is: |authorn= (and aliases) highest and |authors= lowest;
|editorn= (and aliases) highest and |veditors= lowest (support for |editors= withdrawn)

When looking for |authorn= / |editorn= parameters, test |xxxxor1= and |xxxxor2= (and all of their aliases); stops after the second
test which mimicks the test used in extract_names() when looking for a hole in the author name list.  There may be a better
way to do this, I just haven't discovered what that way is.

Emits an error message when more than one xxxxor name source is provided.

In this function, vxxxxors = vauthors or veditors; xxxxors = authors as appropriate.

]]

local function select_author_editor_source (vxxxxors, xxxxors, args, list_name)
 local lastfirst = false;
 if utilities.select_one ( args, cfg.aliases[list_name .. '-Last'], 'none', 1 ) or  -- do this twice in case we have a |first1= without a |last1=; this ...
  utilities.select_one ( args, cfg.aliases[list_name .. '-First'], 'none', 1 ) or  -- ... also catches the case where |first= is used with |vauthors=
  utilities.select_one ( args, cfg.aliases[list_name .. '-Last'], 'none', 2 ) or
  utilities.select_one ( args, cfg.aliases[list_name .. '-First'], 'none', 2 ) then
   lastfirst = true;
 end

 if (utilities.is_set (vxxxxors) and true == lastfirst) or     -- these are the three error conditions
  (utilities.is_set (vxxxxors) and utilities.is_set (xxxxors)) or
  (true == lastfirst and utilities.is_set (xxxxors)) then
   local err_name;
   if 'AuthorList' == list_name then         -- figure out which name should be used in error message
    err_name = 'author';
   else
    err_name = 'editor';
   end
   utilities.set_message ('err_redundant_parameters', err_name .. '-name-list parameters'); -- add error message
 end

 if true == lastfirst then return 1 end;          -- return a number indicating which author name source to use
 if utilities.is_set (vxxxxors) then return 2 end;
 if utilities.is_set (xxxxors) then return 3 end;
 return 1;                 -- no authors so return 1; this allows missing author name test to run in case there is a first without last 
end


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

This function is used to validate a parameter's assigned value for those parameters that have only a limited number
of allowable values (yes, y, true, live, dead, etc.).  When the parameter value has not been assigned a value (missing
or empty in the source template) the function returns the value specified by ret_val.  If the parameter value is one
of the list of allowed values returns the translated value; else, emits an error message and returns the value
specified by ret_val.

TODO: explain <invert>

]]

local function is_valid_parameter_value (value, name, possible, ret_val, invert)
 if not utilities.is_set (value) then
  return ret_val;               -- an empty parameter is ok
 end

 if (not invert and utilities.in_array (value, possible)) then    -- normal; <value> is in <possible> table
  return cfg.keywords_xlate[value];          -- return translation of parameter keyword
 elseif invert and not utilities.in_array (value, possible) then    -- invert; <value> is not in <possible> table
  return value;               -- return <value> as it is
 else
  utilities.set_message ('err_invalid_param_val', {name, value});   -- not an allowed value so add error message
  return ret_val;
 end
end


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

This function terminates a name list (author, contributor, editor) with a separator character (sepc) and a space
when the last character is not a sepc character or when the last three characters are not sepc followed by two
closing square brackets (close of a wikilink).  When either of these is true, the name_list is terminated with a
single space character.

]]

local function terminate_name_list (name_list, sepc)
 if (string.sub (name_list, -3, -1) == sepc .. '. ') then     -- if already properly terminated
  return name_list;              -- just return the name list
 elseif (string.sub (name_list, -1, -1) == sepc) or (string.sub (name_list, -3, -1) == sepc .. ']]') then -- if last name in list ends with sepc char
  return name_list .. " ";            -- don't add another
 else
  return name_list .. sepc .. ' ';          -- otherwise terminate the name list
 end
end


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

returns the concatenation of the formatted volume and issue (or journal article number) parameters as a single
string; or formatted volume or formatted issue, or an empty string if neither are set.

]]
 
local function format_volume_issue (volume, issue, article, cite_class, origin, sepc, lower)
 if not utilities.is_set (volume) and not utilities.is_set (issue) and not utilities.is_set (article) then
  return '';
 end

 -- same condition as in format_pages_sheets()
 local is_journal = 'journal' == cite_class or (utilities.in_array (cite_class, {'citation', 'map', 'interview'}) and 'journal' == origin);

 local is_numeric_vol = volume and (volume:match ('^[MDCLXVI]+$') or volume:match ('^%d+$')); -- is only uppercase roman numerals or only digits?
 local is_long_vol = volume and (4 < mw.ustring.len(volume));    -- is |volume= value longer than 4 characters?
 
 if volume and (not is_numeric_vol and is_long_vol) then      -- when not all digits or Roman numerals, is |volume= longer than 4 characters?
  utilities.add_prop_cat ('long-vol');         -- yes, add properties cat
 end

 if is_journal then               -- journal-style formatting
  local vol = '';

  if utilities.is_set (volume) then
   if is_numeric_vol then            -- |volume= value all digits or all uppercase Roman numerals?
    vol = utilities.substitute (cfg.presentation['vol-bold'], {sepc, volume}); -- render in bold face
   elseif is_long_vol then            -- not all digits or Roman numerals; longer than 4 characters?
    vol = utilities.substitute (cfg.messages['j-vol'], {sepc, utilities.hyphen_to_dash (volume)}); -- not bold
   else                -- four or fewer characters
    vol = utilities.substitute (cfg.presentation['vol-bold'], {sepc, utilities.hyphen_to_dash (volume)}); -- bold
   end
  end
  vol = vol .. (utilities.is_set (issue) and utilities.substitute (cfg.messages['j-issue'], issue) or '')
  vol = vol .. (utilities.is_set (article) and utilities.substitute (cfg.messages['j-article-num'], article) or '')
  return vol;
 end
 
 if 'podcast' == cite_class and utilities.is_set (issue) then
  return wrap_msg ('issue', {sepc, issue}, lower);
 end
 
 if 'conference' == cite_class and utilities.is_set (article) then   -- |article-number= supported only in journal and conference cites
  if utilities.is_set (volume) and utilities.is_set (article) then  -- both volume and article number
   return wrap_msg ('vol-art', {sepc, utilities.hyphen_to_dash (volume), article}, lower);
  elseif utilities.is_set (article) then         -- article number alone; when volume alone, handled below
   return wrap_msg ('art', {sepc, article}, lower);
  end
 end

 -- all other types of citation
 if utilities.is_set (volume) and utilities.is_set (issue) then
  return wrap_msg ('vol-no', {sepc, utilities.hyphen_to_dash (volume), issue}, lower);
 elseif utilities.is_set (volume) then
  return wrap_msg ('vol', {sepc, utilities.hyphen_to_dash (volume)}, lower);
 else
  return wrap_msg ('issue', {sepc, issue}, lower);
 end
end


--[[-------------------------< F O R M A T _ P A G E S _ S H E E T S >-----------------------------------------

adds static text to one of |page(s)= or |sheet(s)= values and returns it with all of the others set to empty strings.
The return order is:
 page, pages, sheet, sheets

Singular has priority over plural when both are provided.

]]

local function format_pages_sheets (page, pages, sheet, sheets, cite_class, origin, sepc, nopp, lower)
 if 'map' == cite_class then             -- only cite map supports sheet(s) as in-source locators
  if utilities.is_set (sheet) then
   if 'journal' == origin then
    return '', '', wrap_msg ('j-sheet', sheet, lower), '';
   else
    return '', '', wrap_msg ('sheet', {sepc, sheet}, lower), '';
   end
  elseif utilities.is_set (sheets) then
   if 'journal' == origin then
    return '', '', '', wrap_msg ('j-sheets', sheets, lower);
   else
    return '', '', '', wrap_msg ('sheets', {sepc, sheets}, lower);
   end
  end
 end

 local is_journal = 'journal' == cite_class or (utilities.in_array (cite_class, {'citation', 'map', 'interview'}) and 'journal' == origin);
 
 if utilities.is_set (page) then
  if is_journal then
   return utilities.substitute (cfg.messages['j-page(s)'], page), '', '', '';
  elseif not nopp then
   return utilities.substitute (cfg.messages['p-prefix'], {sepc, page}), '', '', '';
  else
   return utilities.substitute (cfg.messages['nopp'], {sepc, page}), '', '', '';
  end
 elseif utilities.is_set (pages) then
  if is_journal then
   return utilities.substitute (cfg.messages['j-page(s)'], pages), '', '', '';
  elseif tonumber(pages) ~= nil and not nopp then       -- if pages is only digits, assume a single page number
   return '', utilities.substitute (cfg.messages['p-prefix'], {sepc, pages}), '', '';
  elseif not nopp then
   return '', utilities.substitute (cfg.messages['pp-prefix'], {sepc, pages}), '', '';
  else
   return '', utilities.substitute (cfg.messages['nopp'], {sepc, pages}), '', '';
  end
 end
 
 return '', '', '', '';              -- return empty strings
end


--[[--------------------------< I N S O U R C E _ L O C _ G E T >----------------------------------------------

returns one of the in-source locators: page, pages, or at. 

If any of these are interwiki links to Wikisource, returns the label portion of the interwiki-link as plain text
for use in COinS.  This COinS thing is done because here we convert an interwiki-link to an external link and
add an icon span around that; get_coins_pages() doesn't know about the span.  TODO: should it?  

TODO: add support for sheet and sheets?; streamline;

TODO: make it so that this function returns only one of the three as the single in-source (the return value assigned
to a new name)?

]]

local function insource_loc_get (page, page_orig, pages, pages_orig, at)
 local ws_url, ws_label, coins_pages, L;          -- for Wikisource interwiki-links; TODO: this corrupts page metadata (span remains in place after cleanup; fix there?)

 if utilities.is_set (page) then
  if utilities.is_set (pages) or utilities.is_set (at) then
   pages = '';               -- unset the others
   at = '';
  end
  extra_text_in_page_check (page, page_orig);        -- emit error message when |page= value begins with what looks like p., pp., etc.

  ws_url, ws_label, L = wikisource_url_make (page);      -- make ws URL from |page= interwiki link; link portion L becomes tooltip label
  if ws_url then
   page = external_link (ws_url, ws_label .. '&nbsp;', 'ws link in page'); -- space char after label to move icon away from in-source text; TODO: a better way to do this?
   page = utilities.substitute (cfg.presentation['interwiki-icon'], {cfg.presentation['class-wikisource'], L, page});
   coins_pages = ws_label;
  end
 elseif utilities.is_set (pages) then
  if utilities.is_set (at) then
   at = '';               -- unset
  end
  extra_text_in_page_check (pages, pages_orig);       -- emit error message when |page= value begins with what looks like p., pp., etc.

  ws_url, ws_label, L = wikisource_url_make (pages);      -- make ws URL from |pages= interwiki link; link portion L becomes tooltip label
  if ws_url then
   pages = external_link (ws_url, ws_label .. '&nbsp;', 'ws link in pages'); -- space char after label to move icon away from in-source text; TODO: a better way to do this?
   pages = utilities.substitute (cfg.presentation['interwiki-icon'], {cfg.presentation['class-wikisource'], L, pages});
   coins_pages = ws_label;
  end
 elseif utilities.is_set (at) then
  ws_url, ws_label, L = wikisource_url_make (at);       -- make ws URL from |at= interwiki link; link portion L becomes tooltip label
  if ws_url then
   at = external_link (ws_url, ws_label .. '&nbsp;', 'ws link in at'); -- space char after label to move icon away from in-source text; TODO: a better way to do this?
   at = utilities.substitute (cfg.presentation['interwiki-icon'], {cfg.presentation['class-wikisource'], L, at});
   coins_pages = ws_label;
  end
 end
 
 return page, pages, at, coins_pages;
end

--[[--------------------------< I S _ U N I Q U E _ A R C H I V E _ U R L >------------------------------------

add error message when |archive-url= value is same as |url= or chapter-url= (or alias...) value

]]

local function is_unique_archive_url (archive, url, c_url, source, date)
 if utilities.is_set (archive) then
  if archive == url or archive == c_url then
   utilities.set_message ('err_bad_url', {utilities.wrap_style ('parameter', source)}); -- add error message
   return '', '';              -- unset |archive-url= and |archive-date= because same as |url= or |chapter-url=
  end
 end

 return archive, date;
end


--[=[-------------------------< A R C H I V E _ U R L _ C H E C K >--------------------------------------------

Check archive.org URLs to make sure they at least look like they are pointing at valid archives and not to the 
save snapshot URL or to calendar pages.  When the archive URL is 'https://web.archive.org/save/' (or http://...)
archive.org saves a snapshot of the target page in the URL.  That is something that Wikipedia should not allow
unwitting readers to do.

When the archive.org URL does not have a complete timestamp, archive.org chooses a snapshot according to its own
algorithm or provides a calendar 'search' result.  [[WP:ELNO]] discourages links to search results.

This function looks at the value assigned to |archive-url= and returns empty strings for |archive-url= and
|archive-date= and an error message when:
 |archive-url= holds an archive.org save command URL
 |archive-url= is an archive.org URL that does not have a complete timestamp (YYYYMMDDhhmmss 14 digits) in the
  correct place
otherwise returns |archive-url= and |archive-date=

There are two mostly compatible archive.org URLs:
 //web.archive.org/<timestamp>...  -- the old form
 //web.archive.org/web/<timestamp>... -- the new form

The old form does not support or map to the new form when it contains a display flag.  There are four identified flags
('id_', 'js_', 'cs_', 'im_') but since archive.org ignores others following the same form (two letters and an underscore)
we don't check for these specific flags but we do check the form.

This function supports a preview mode.  When the article is rendered in preview mode, this function may return a modified
archive URL:
 for save command errors, return undated wildcard (/*/)
 for timestamp errors when the timestamp has a wildcard, return the URL unmodified
 for timestamp errors when the timestamp does not have a wildcard, return with timestamp limited to six digits plus wildcard (/yyyymm*/)

A secondary function is to return an archive-url timestamp from those urls that have them (archive.org and
archive.today).  The timestamp is used by validation.archive_date_check() to see if the value in |archive-date=
matches the timestamp in the archive url.

]=]

local function archive_url_check (url, date)
 local err_msg = '';               -- start with the error message empty
 local path, timestamp, flag;            -- portions of the archive.org URL
 
 timestamp = url:match ('//archive.today/(%d%d%d%d%d%d%d%d%d%d%d%d%d%d)/') or -- get timestamp from archive.today urls
  url:match ('//archive.today/(%d%d%d%d%.%d%d%.%d%d%-%d%d%d%d%d%d)/');  -- this timestamp needs cleanup
 if timestamp then               -- if this was an archive.today url ...
  return url, date, timestamp:gsub ('[%.%-]', '');      -- return ArchiveURL, ArchiveDate, and timestamp (dots and dashes removed) from |archive-url=, and done
 end
                    -- here for archive.org urls
 if (not url:match('//web%.archive%.org/')) and (not url:match('//liveweb%.archive%.org/')) then  -- also deprecated liveweb Wayback machine URL
  return url, date;              -- not an archive.org archive, return ArchiveURL and ArchiveDate
 end

 if url:match('//web%.archive%.org/save/') then        -- if a save command URL, we don't want to allow saving of the target page 
  err_msg = cfg.err_msg_supl.save;
  url = url:gsub ('(//web%.archive%.org)/save/', '%1/*/', 1);    -- for preview mode: modify ArchiveURL
 elseif url:match('//liveweb%.archive%.org/') then
  err_msg = cfg.err_msg_supl.liveweb;
 else
  path, timestamp, flag = url:match('//web%.archive%.org/([^%d]*)(%d+)([^/]*)/'); -- split out some of the URL parts for evaluation
  if not path then              -- malformed in some way; pattern did not match
   err_msg = cfg.err_msg_supl.timestamp;
  elseif 14 ~= timestamp:len() then          -- path and flag optional, must have 14-digit timestamp here
   err_msg = cfg.err_msg_supl.timestamp;
   if '*' ~= flag then
    local replacement = timestamp:match ('^%d%d%d%d%d%d') or timestamp:match ('^%d%d%d%d'); -- get the first 6 (YYYYMM) or first 4 digits (YYYY)
    if replacement then            -- nil if there aren't at least 4 digits (year)
     replacement = replacement .. string.rep ('0', 14 - replacement:len()); -- year or yearmo (4 or 6 digits) zero-fill to make 14-digit timestamp
     url=url:gsub ('(//web%.archive%.org/[^%d]*)%d[^/]*', '%1' .. replacement .. '*', 1) -- for preview, modify ts to 14 digits plus splat for calendar display
    end
   end
  elseif utilities.is_set (path) and 'web/' ~= path then     -- older archive URLs do not have the extra 'web/' path element
   err_msg = cfg.err_msg_supl.path;
  elseif utilities.is_set (flag) and not utilities.is_set (path) then  -- flag not allowed with the old form URL (without the 'web/' path element)
   err_msg = cfg.err_msg_supl.flag;
  elseif utilities.is_set (flag) and not flag:match ('%a%a_') then  -- flag if present must be two alpha characters and underscore (requires 'web/' path element)
   err_msg = cfg.err_msg_supl.flag;
  else
   return url, date, timestamp;          -- return ArchiveURL, ArchiveDate, and timestamp from |archive-url=
  end
 end
                    -- if here, something not right so
 utilities.set_message ('err_archive_url', {err_msg});      -- add error message and

 if is_preview_mode then
  return url, date, timestamp;           -- preview mode so return ArchiveURL, ArchiveDate, and timestamp from |archive-url=
 else
  return '', '';               -- return empty strings for ArchiveURL and ArchiveDate
 end
end


--[[--------------------------< P L A C E _ C H E C K >--------------------------------------------------------

check |place=, |publication-place=, |location= to see if these params include digits.  This function added because
many editors misuse location to specify the in-source location (|page(s)= and |at= are supposed to do that)

returns the original parameter value without modification; added maint cat when parameter value contains digits

]]

local function place_check (param_val)
 if not utilities.is_set (param_val) then         -- parameter empty or omitted
  return param_val;              -- return that empty state
 end
 
 if mw.ustring.find (param_val, '%d') then         -- not empty, are there digits in the parameter value
  utilities.set_message ('maint_location');        -- yep, add maint cat
 end
 
 return param_val;               -- and done
end


--[[--------------------------< I S _ A R C H I V E D _ C O P Y >----------------------------------------------

compares |title= to 'Archived copy' (placeholder added by bots that can't find proper title); if matches, return true; nil else

]]

local function is_archived_copy (title)
 title = mw.ustring.lower(title);           -- switch title to lower case
 if title:find (cfg.special_case_translation.archived_copy.en) then   -- if title is 'Archived copy'
  return true;
 elseif cfg.special_case_translation.archived_copy['local'] then
  if mw.ustring.find (title, cfg.special_case_translation.archived_copy['local']) then -- mw.ustring() because might not be Latin script
   return true;
  end
 end
end


--[[--------------------------< D I S P L A Y _ N A M E S _ S E L E C T >--------------------------------------

for any of the |display-authors=, |display-editors=, etc parameters, select either the local or global setting.
When both are present, look at <local_display_names> value.  When the value is some sort of 'et al.'string,
special handling is required.

When {{cs1 config}} has |display-<namelist>= AND this template has |display-<namelist>=etal AND:
 the number of names specified by <number_of_names> is:
  greater than the number specified in the global |display-<namelist>= parameter (<global_display_names>)
   use global |display-<namelist>= parameter value
   set overridden maint category
  less than or equal to the number specified in the global |display-<namelist>=  parameter
   use local |display-<namelist>= parameter value

The purpose of this function is to prevent categorizing a template that has fewer names than the global setting
to keep the etal annotation specified by <local_display_names>.

]]

local function display_names_select (global_display_names, local_display_names, param_name, number_of_names, test)
 if global_display_names and utilities.is_set (local_display_names) then  -- when both
  if 'etal' == local_display_names:lower():gsub("[ '%.]", '') then  -- the :gsub() portion makes 'etal' from a variety of 'et al.' spellings and stylings
   number_of_names = tonumber (number_of_names);      -- convert these to numbers for comparison
   local global_display_names_num = tonumber (global_display_names); -- <global_display_names> not set when parameter value is not digits

   if number_of_names > global_display_names_num then     -- template has more names than global config allows to be displayed?
    utilities.set_message ('maint_overridden_setting');    -- set a maint message because global is overriding local |display-<namelist>=etal
    return global_display_names, 'cs1 config';      -- return global with spoof parameter name (for get_display_names())
   else
    return local_display_names, param_name;       -- return local because fewer names so let <local_display_names> control
   end
  end
                    -- here when <global_display_names> and <local_display_names> both numbers; <global_display_names> controls
  utilities.set_message ('maint_overridden_setting');      -- set a maint message
  return global_display_names, 'cs1 config';        -- return global with spoof parameter name (for get_display_names())
 end
                    -- here when only one of <global_display_names> or <local_display_names> set
 if global_display_names then
  return global_display_names, 'cs1 config';        -- return global with spoof parameter name (for get_display_names())
 else
  return local_display_names, param_name;         -- return local
 end
end


--[[--------------------------< C I T A T I O N 0 >------------------------------------------------------------

This is the main function doing the majority of the citation formatting.

]]

local function citation0( config, args )
 --[[ 
 Load Input Parameters
 The argument_wrapper facilitates the mapping of multiple aliases to single internal variable.
 ]]
 local A = argument_wrapper ( args );
 local i 

 -- Pick out the relevant fields from the arguments.  Different citation templates
 -- define different field names for the same underlying things. 

 local author_etal;
 local a = {};                -- authors list from |lastn= / |firstn= pairs or |vauthors=
 local Authors;
 local NameListStyle;
  if cfg.global_cs1_config_t['NameListStyle'] then      -- global setting in {{cs1 config}} overrides local |name-list-style= parameter value; nil when empty or assigned value invalid
   NameListStyle = is_valid_parameter_value (cfg.global_cs1_config_t['NameListStyle'], 'cs1 config: name-list-style', cfg.keywords_lists['name-list-style'], ''); -- error messaging 'param' here is a hoax
  else
   NameListStyle = is_valid_parameter_value (A['NameListStyle'], A:ORIGIN('NameListStyle'), cfg.keywords_lists['name-list-style'], '');
  end

  if cfg.global_cs1_config_t['NameListStyle'] and utilities.is_set (A['NameListStyle']) then -- when template has |name-list-style=<something> which global setting has overridden
   utilities.set_message ('maint_overridden_setting');     -- set a maint message
  end

 local Collaboration = A['Collaboration'];

 do                   -- to limit scope of selected
  local selected = select_author_editor_source (A['Vauthors'], A['Authors'], args, 'AuthorList');
  if 1 == selected then
   a, author_etal = extract_names (args, 'AuthorList');    -- fetch author list from |authorn= / |lastn= / |firstn=, |author-linkn=, and |author-maskn=
  elseif 2 == selected then
   NameListStyle = 'vanc';            -- override whatever |name-list-style= might be
   a, author_etal = parse_vauthors_veditors (args, A['Vauthors'], 'AuthorList'); -- fetch author list from |vauthors=, |author-linkn=, and |author-maskn=
  elseif 3 == selected then
   Authors = A['Authors'];            -- use content of |people= or |credits=; |authors= is deprecated; TODO: constrain |people= and |credits= to cite av media, episode, serial?
  end
  if utilities.is_set (Collaboration) then
   author_etal = true;             -- so that |display-authors=etal not required
  end
 end

 local editor_etal;
 local e = {};                -- editors list from |editor-lastn= / |editor-firstn= pairs or |veditors=

 do                   -- to limit scope of selected
  local selected = select_author_editor_source (A['Veditors'], nil, args, 'EditorList'); -- support for |editors= withdrawn
  if 1 == selected then
   e, editor_etal = extract_names (args, 'EditorList');    -- fetch editor list from |editorn= / |editor-lastn= / |editor-firstn=, |editor-linkn=, and |editor-maskn=
  elseif 2 == selected then
   NameListStyle = 'vanc';            -- override whatever |name-list-style= might be
   e, editor_etal = parse_vauthors_veditors (args, args.veditors, 'EditorList'); -- fetch editor list from |veditors=, |editor-linkn=, and |editor-maskn=
  end
 end
       
 local Chapter = A['Chapter'];            -- done here so that we have access to |contribution= from |chapter= aliases
 local Chapter_origin = A:ORIGIN ('Chapter');
 local Contribution;               -- because contribution is required for contributor(s)
  if 'contribution' == Chapter_origin then
   Contribution = Chapter;            -- get the name of the contribution
  end
 local c = {};                -- contributors list from |contributor-lastn= / contributor-firstn= pairs
 
 if utilities.in_array (config.CitationClass, {"book", "citation"}) and not utilities.is_set (A['Periodical']) then -- |contributor= and |contribution= only supported in book cites
  c = extract_names (args, 'ContributorList');       -- fetch contributor list from |contributorn= / |contributor-lastn=, -firstn=, -linkn=, -maskn=
  
  if 0 < #c then
   if not utilities.is_set (Contribution) then       -- |contributor= requires |contribution=
    utilities.set_message ('err_contributor_missing_required_param', 'contribution'); -- add missing contribution error message
    c = {};               -- blank the contributors' table; it is used as a flag later
   end
   if 0 == #a then              -- |contributor= requires |author=
    utilities.set_message ('err_contributor_missing_required_param', 'author'); -- add missing author error message
    c = {};               -- blank the contributors' table; it is used as a flag later
   end
  end
 else                  -- if not a book cite
  if utilities.select_one (args, cfg.aliases['ContributorList-Last'], 'err_redundant_parameters', 1 ) then -- are there contributor name list parameters?
   utilities.set_message ('err_contributor_ignored');     -- add contributor ignored error message
  end
  Contribution = nil;              -- unset
 end

 local Title = A['Title'];
 local TitleLink = A['TitleLink'];

 local auto_select = '';              -- default is auto
 local accept_link;
 TitleLink, accept_link = utilities.has_accept_as_written (TitleLink, true); -- test for accept-this-as-written markup
 if (not accept_link) and utilities.in_array (TitleLink, {'none', 'pmc', 'doi'}) then -- check for special keywords
  auto_select = TitleLink;            -- remember selection for later
  TitleLink = '';               -- treat as if |title-link= would have been empty
 end

 TitleLink = link_title_ok (TitleLink, A:ORIGIN ('TitleLink'), Title, 'title'); -- check for wiki-markup in |title-link= or wiki-markup in |title= when |title-link= is set

 local Section = '';               -- {{cite map}} only; preset to empty string for concatenation if not used
 if 'map' == config.CitationClass and 'section' == Chapter_origin then
  Section = A['Chapter'];             -- get |section= from |chapter= alias list; |chapter= and the other aliases not supported in {{cite map}}
  Chapter = '';               -- unset for now; will be reset later from |map= if present
 end

 local Periodical = A['Periodical'];
 local Periodical_origin = A:ORIGIN('Periodical');
 local ScriptPeriodical = A['ScriptPeriodical'];
 local ScriptPeriodical_origin = A:ORIGIN('ScriptPeriodical');
 local TransPeriodical =  A['TransPeriodical'];
 local TransPeriodical_origin =  A:ORIGIN ('TransPeriodical');
 
 if (utilities.in_array (config.CitationClass, {'book', 'encyclopaedia'}) and (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical) or utilities.is_set (TransPeriodical))) then
  local param;
  if utilities.is_set (Periodical) then         -- get a parameter name from one of these periodical related meta-parameters
   Periodical = '';             -- unset because not valid {{cite book}} or {{cite encyclopedia}} parameters 
   param = Periodical_origin           -- get parameter name for error messaging
  elseif utilities.is_set (TransPeriodical) then
   TransPeriodical = '';            -- unset because not valid {{cite book}} or {{cite encyclopedia}} parameters 
   param = TransPeriodical_origin;          -- get parameter name for error messaging
  elseif utilities.is_set (ScriptPeriodical) then
   ScriptPeriodical = '';            -- unset because not valid {{cite book}} or {{cite encyclopedia}} parameters 
   param = ScriptPeriodical_origin;         -- get parameter name for error messaging
  end

  if utilities.is_set (param) then          -- if we found one
   utilities.set_message ('err_periodical_ignored', {param});   -- emit an error message
  end
 end

 if utilities.is_set (Periodical) then
  local i;
  Periodical, i = utilities.strip_apostrophe_markup (Periodical);   -- strip apostrophe markup so that metadata isn't contaminated 
  if i then                -- non-zero when markup was stripped so emit an error message
   utilities.set_message ('err_apostrophe_markup', {Periodical_origin});
  end
 end

 if 'mailinglist' == config.CitationClass then        -- special case for {{cite mailing list}}
  if utilities.is_set (Periodical) and utilities.is_set (A ['MailingList']) then -- both set emit an error TODO: make a function for this and similar?
   utilities.set_message ('err_redundant_parameters', {utilities.wrap_style ('parameter', Periodical_origin) .. cfg.presentation['sep_list_pair'] .. utilities.wrap_style ('parameter', 'mailinglist')});
  end

  Periodical = A ['MailingList'];           -- error or no, set Periodical to |mailinglist= value because this template is {{cite mailing list}}
  Periodical_origin = A:ORIGIN('MailingList');
 end

 -- web and news not tested for now because of 
 -- Wikipedia:Administrators%27_noticeboard#Is_there_a_semi-automated_tool_that_could_fix_these_annoying_"Cite_Web"_errors?
 if not (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical)) then -- 'periodical' templates require periodical parameter
 -- local p = {['journal'] = 'journal', ['magazine'] = 'magazine', ['news'] = 'newspaper', ['web'] = 'website'}; -- for error message
  local p = {['journal'] = 'journal', ['magazine'] = 'magazine'};   -- for error message
  if p[config.CitationClass]  then
   utilities.set_message ('err_missing_periodical', {config.CitationClass, p[config.CitationClass]});
  end
 end
 
 local Volume;
 if 'citation' == config.CitationClass then
  if utilities.is_set (Periodical) then
   if not utilities.in_array (Periodical_origin, cfg.citation_no_volume_t) then -- {{citation}} does not render |volume= when these parameters are used
    Volume = A['Volume'];           -- but does for all other 'periodicals'
   end
  elseif utilities.is_set (ScriptPeriodical) then
   if 'script-website' ~= ScriptPeriodical_origin then     -- {{citation}} does not render volume for |script-website=
    Volume = A['Volume'];           -- but does for all other 'periodicals'
   end
  else
   Volume = A['Volume'];            -- and does for non-'periodical' cites
  end
 elseif utilities.in_array (config.CitationClass, cfg.templates_using_volume) then -- render |volume= for cs1 according to the configuration settings
  Volume = A['Volume'];
 end 
 extra_text_in_vol_iss_check (Volume, A:ORIGIN ('Volume'), 'v'); 

 local Issue;
 if 'citation' == config.CitationClass then
  if utilities.is_set (Periodical) and utilities.in_array (Periodical_origin, cfg.citation_issue_t) then -- {{citation}} may render |issue= when these parameters are used
   Issue = utilities.hyphen_to_dash (A['Issue']);
  end
 elseif utilities.in_array (config.CitationClass, cfg.templates_using_issue) then -- conference & map books do not support issue; {{citation}} listed here because included in settings table
  if not (utilities.in_array (config.CitationClass, {'conference', 'map', 'citation'}) and not (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical))) then
   Issue = utilities.hyphen_to_dash (A['Issue']);
  end
 end
 
 local ArticleNumber;

 if utilities.in_array (config.CitationClass, {'journal', 'conference'}) or ('citation' == config.CitationClass and utilities.is_set (Periodical) and 'journal' == Periodical_origin) then
  ArticleNumber = A['ArticleNumber'];
 end

 extra_text_in_vol_iss_check (Issue, A:ORIGIN ('Issue'), 'i'); 

 local Page;
 local Pages;
 local At;
 local QuotePage;
 local QuotePages;
 if not utilities.in_array (config.CitationClass, cfg.templates_not_using_page) then  -- TODO: rewrite to emit ignored parameter error message?
  Page = A['Page'];
  Pages = utilities.hyphen_to_dash (A['Pages']); 
  At = A['At'];
  QuotePage = A['QuotePage'];
  QuotePages = utilities.hyphen_to_dash (A['QuotePages']);
 end

 local Edition = A['Edition'];
 local PublicationPlace = place_check (A['PublicationPlace'], A:ORIGIN('PublicationPlace'));
 local Place = place_check (A['Place'], A:ORIGIN('Place'));
 
 local PublisherName = A['PublisherName'];
 local PublisherName_origin = A:ORIGIN('PublisherName');
 if utilities.is_set (PublisherName) and (cfg.keywords_xlate['none'] ~= PublisherName) then
  local i = 0;
  PublisherName, i = utilities.strip_apostrophe_markup (PublisherName); -- strip apostrophe markup so that metadata isn't contaminated; publisher is never italicized
  if i and (0 <i) then             -- non-zero when markup was stripped so emit an error message
   utilities.set_message ('err_apostrophe_markup', {PublisherName_origin});
  end
 end
 
 if ('document' == config.CitationClass) and not utilities.is_set (PublisherName) then
  utilities.set_message ('err_missing_publisher', {config.CitationClass, 'publisher'});
 end

 local Newsgroup = A['Newsgroup'];           -- TODO: strip apostrophe markup?
 local Newsgroup_origin = A:ORIGIN('Newsgroup'); 

 if 'newsgroup' == config.CitationClass then
  if utilities.is_set (PublisherName) and (cfg.keywords_xlate['none'] ~= PublisherName) then -- general use parameter |publisher= not allowed in cite newsgroup
   utilities.set_message ('err_parameter_ignored', {PublisherName_origin});
  end

  PublisherName = nil;             -- ensure that this parameter is unset for the time being; will be used again after COinS
 end

 local URL = A['URL'];              -- TODO: better way to do this for URL, ChapterURL, and MapURL?
 local UrlAccess = is_valid_parameter_value (A['UrlAccess'], A:ORIGIN('UrlAccess'), cfg.keywords_lists['url-access'], nil);
 
 if not utilities.is_set (URL) and utilities.is_set (UrlAccess) then
  UrlAccess = nil;
  utilities.set_message ('err_param_access_requires_param', 'url');
 end
 
 local ChapterURL = A['ChapterURL'];
 local ChapterUrlAccess = is_valid_parameter_value (A['ChapterUrlAccess'], A:ORIGIN('ChapterUrlAccess'), cfg.keywords_lists['url-access'], nil);
 if not utilities.is_set (ChapterURL) and utilities.is_set (ChapterUrlAccess) then
  ChapterUrlAccess = nil;
  utilities.set_message ('err_param_access_requires_param', {A:ORIGIN('ChapterUrlAccess'):gsub ('%-access', '')});
 end

 local MapUrlAccess = is_valid_parameter_value (A['MapUrlAccess'], A:ORIGIN('MapUrlAccess'), cfg.keywords_lists['url-access'], nil);
 if not utilities.is_set (A['MapURL']) and utilities.is_set (MapUrlAccess) then
  MapUrlAccess = nil;
  utilities.set_message ('err_param_access_requires_param', {'map-url'});
 end

 local this_page = mw.title.getCurrentTitle();        -- also used for COinS and for language
 local no_tracking_cats = is_valid_parameter_value (A['NoTracking'], A:ORIGIN('NoTracking'), cfg.keywords_lists['yes_true_y'], nil);

 -- check this page to see if it is in one of the namespaces that cs1 is not supposed to add to the error categories
 if not utilities.is_set (no_tracking_cats) then        -- ignore if we are already not going to categorize this page
  if cfg.uncategorized_namespaces[this_page.namespace] then    -- is this page's namespace id one of the uncategorized namespace ids?
   no_tracking_cats = "true";           -- set no_tracking_cats
  end
  for _, v in ipairs (cfg.uncategorized_subpages) do      -- cycle through page name patterns
   if this_page.text:match (v) then         -- test page name against each pattern
    no_tracking_cats = "true";          -- set no_tracking_cats
    break;               -- bail out if one is found
   end
  end
 end
                    -- check for extra |page=, |pages= or |at= parameters. (also sheet and sheets while we're at it)
 utilities.select_one (args, {'page', 'p', 'pp', 'pages', 'at', 'sheet', 'sheets'}, 'err_redundant_parameters'); -- this is a dummy call simply to get the error message and category

 local coins_pages;
 
 Page, Pages, At, coins_pages = insource_loc_get (Page, A:ORIGIN('Page'), Pages, A:ORIGIN('Pages'), At);

 local NoPP = is_valid_parameter_value (A['NoPP'], A:ORIGIN('NoPP'), cfg.keywords_lists['yes_true_y'], nil);

 if utilities.is_set (PublicationPlace) and utilities.is_set (Place) then -- both |publication-place= and |place= (|location=) allowed if different
  utilities.add_prop_cat ('location-test');        -- add property cat to evaluate how often PublicationPlace and Place are used together
  if PublicationPlace == Place then
   Place = '';               -- unset; don't need both if they are the same
  end
 elseif not utilities.is_set (PublicationPlace) and utilities.is_set (Place) then -- when only |place= (|location=) is set ...
  PublicationPlace = Place;            -- promote |place= (|location=) to |publication-place
 end

 if PublicationPlace == Place then Place = ''; end       -- don't need both if they are the same

 local URL_origin = A:ORIGIN('URL');           -- get name of parameter that holds URL
 local ChapterURL_origin = A:ORIGIN('ChapterURL');       -- get name of parameter that holds ChapterURL
 local ScriptChapter = A['ScriptChapter'];
 local ScriptChapter_origin = A:ORIGIN ('ScriptChapter');
 local Format = A['Format'];
 local ChapterFormat = A['ChapterFormat'];
 local TransChapter = A['TransChapter'];
 local TransChapter_origin = A:ORIGIN ('TransChapter');
 local TransTitle = A['TransTitle'];
 local ScriptTitle = A['ScriptTitle'];
 
 --[[
 Parameter remapping for cite encyclopedia:
 When the citation has these parameters:
  |encyclopedia= and |title= then map |title= to |article= and |encyclopedia= to |title= for rendering
  |encyclopedia= and |article= then map |encyclopedia= to |title= for rendering

  |trans-title= maps to |trans-chapter= when |title= is re-mapped
  |url= maps to |chapter-url= when |title= is remapped
 
 All other combinations of |encyclopedia=, |title=, and |article= are not modified
 
 ]]

 local Encyclopedia = A['Encyclopedia'];          -- used as a flag by this module and by ~/COinS
 local ScriptEncyclopedia = A['ScriptEncyclopedia'];
 local TransEncyclopedia = A['TransEncyclopedia'];

 if utilities.is_set (Encyclopedia) or utilities.is_set (ScriptEncyclopedia) then -- emit error message when Encyclopedia set but template is other than {{cite encyclopedia}} or {{citation}}
  if 'encyclopaedia' ~= config.CitationClass and 'citation' ~= config.CitationClass then
   if utilities.is_set (Encyclopedia) then
    utilities.set_message ('err_parameter_ignored', {A:ORIGIN ('Encyclopedia')});
   else
    utilities.set_message ('err_parameter_ignored', {A:ORIGIN ('ScriptEncyclopedia')});
   end
   Encyclopedia = nil;             -- unset these because not supported by this template
   ScriptEncyclopedia = nil;
   TransEncyclopedia = nil;
  end
 elseif utilities.is_set (TransEncyclopedia) then
  utilities.set_message ('err_trans_missing_title', {'encyclopedia'});
 end

 if ('encyclopaedia' == config.CitationClass) or ('citation' == config.CitationClass and utilities.is_set (Encyclopedia)) then
  if utilities.is_set (Periodical) and utilities.is_set (Encyclopedia) then -- when both parameters set emit an error message; {{citation}} only; Periodical not allowed in {{cite encyclopedia}}
   utilities.set_message ('err_periodical_ignored', {Periodical_origin});
  end

  if utilities.is_set (Encyclopedia) or utilities.is_set (ScriptEncyclopedia) then
   Periodical = Encyclopedia;           -- error or no, set Periodical to Encyclopedia for rendering; {{citation}} could (not legitimately) have both; use Encyclopedia
   Periodical_origin = A:ORIGIN ('Encyclopedia');
   ScriptPeriodical = ScriptEncyclopedia;
   ScriptPeriodical_origin = A:ORIGIN ('ScriptEncyclopedia');

   if utilities.is_set (Title) or utilities.is_set (ScriptTitle) then
    if not utilities.is_set (Chapter) then
     Chapter = Title;           -- |encyclopedia= and |title= are set so map |title= params to |article= params for rendering
     ScriptChapter = ScriptTitle;
     ScriptChapter_origin = A:ORIGIN('ScriptTitle')
     TransChapter = TransTitle;
     ChapterURL = URL;
     ChapterURL_origin = URL_origin;
     ChapterUrlAccess = UrlAccess;
     ChapterFormat = Format;

     if not utilities.is_set (ChapterURL) and utilities.is_set (TitleLink) then
      Chapter = utilities.make_wikilink (TitleLink, Chapter);
     end
     Title = Periodical;           -- now map |encyclopedia= params to |title= params for rendering
     ScriptTitle = ScriptPeriodical or '';
     TransTitle = TransEncyclopedia or '';
     Periodical = '';           -- redundant so unset
     ScriptPeriodical = '';
     URL = '';
     Format = '';
     TitleLink = '';
    end
   elseif utilities.is_set (Chapter) or utilities.is_set (ScriptChapter) then -- |title= not set
    Title = Periodical;            -- |encyclopedia= set and |article= set so map |encyclopedia= to |title= for rendering
    ScriptTitle = ScriptPeriodical or '';
    TransTitle = TransEncyclopedia or '';
    Periodical = '';            -- redundant so unset
    ScriptPeriodical = '';
   end
  end
 end

 -- special case for cite techreport.
 local ID = A['ID'];
 if (config.CitationClass == "techreport") then        -- special case for cite techreport
  if utilities.is_set (A['Number']) then         -- cite techreport uses 'number', which other citations alias to 'issue'
   if not utilities.is_set (ID) then         -- can we use ID for the "number"?
    ID = A['Number'];            -- yes, use it
   else                -- ID has a value so emit error message
    utilities.set_message ('err_redundant_parameters', {utilities.wrap_style ('parameter', 'id') .. cfg.presentation['sep_list_pair'] .. utilities.wrap_style ('parameter', 'number')});
   end
  end 
 end

 -- Account for the oddity that is {{cite conference}}, before generation of COinS data.
 local ChapterLink -- = A['ChapterLink'];         -- deprecated as a parameter but still used internally by cite episode
 local Conference = A['Conference'];
 local BookTitle = A['BookTitle'];
 local TransTitle_origin = A:ORIGIN ('TransTitle');
 if 'conference' == config.CitationClass then
  if utilities.is_set (BookTitle) then
   Chapter = Title;
   Chapter_origin = 'title';
 --  ChapterLink = TitleLink;           -- |chapter-link= is deprecated
   ChapterURL = URL;
   ChapterUrlAccess = UrlAccess;
   ChapterURL_origin = URL_origin;
   URL_origin = '';
   ChapterFormat = Format;
   TransChapter = TransTitle;
   TransChapter_origin = TransTitle_origin;
   Title = BookTitle;
   Format = '';
 --  TitleLink = '';
   TransTitle = '';
   URL = '';
  end
 elseif 'speech' ~= config.CitationClass then
  Conference = '';              -- not cite conference or cite speech so make sure this is empty string
 end
 
 -- CS1/2 mode
 local Mode;
  if cfg.global_cs1_config_t['Mode'] then         -- global setting in {{cs1 config}} overrides local |mode= parameter value; nil when empty or assigned value invalid
   Mode = is_valid_parameter_value (cfg.global_cs1_config_t['Mode'], 'cs1 config: mode', cfg.keywords_lists['mode'], ''); -- error messaging 'param' here is a hoax
  else
   Mode = is_valid_parameter_value (A['Mode'], A:ORIGIN('Mode'), cfg.keywords_lists['mode'], '');
  end

  if cfg.global_cs1_config_t['Mode'] and utilities.is_set (A['Mode']) then -- when template has |mode=<something> which global setting has overridden
   utilities.set_message ('maint_overridden_setting');     -- set a maint message
  end

 -- separator character and postscript
 local sepc, PostScript = set_style (Mode:lower(), A['PostScript'], config.CitationClass);
 -- controls capitalization of certain static text
 local use_lowercase = ( sepc == ',' );
 
 -- cite map oddities
 local Cartography = "";
 local Scale = "";
 local Sheet = A['Sheet'] or '';
 local Sheets = A['Sheets'] or '';
 if config.CitationClass == "map" then
  if utilities.is_set (Chapter) then          --TODO: make a function for this and similar?
   utilities.set_message ('err_redundant_parameters', {utilities.wrap_style ('parameter', 'map') .. cfg.presentation['sep_list_pair'] .. utilities.wrap_style ('parameter', Chapter_origin)}); -- add error message
  end
  Chapter = A['Map'];
  Chapter_origin = A:ORIGIN('Map');
  ChapterURL = A['MapURL'];
  ChapterURL_origin = A:ORIGIN('MapURL');
  TransChapter = A['TransMap'];
  ScriptChapter = A['ScriptMap']
  ScriptChapter_origin = A:ORIGIN('ScriptMap')

  ChapterUrlAccess = MapUrlAccess;
  ChapterFormat = A['MapFormat'];

  Cartography = A['Cartography'];
  if utilities.is_set ( Cartography ) then
   Cartography = sepc .. "『 .. wrap_msg ('cartography', Cartography, use_lowercase);
  end  
  Scale = A['Scale'];
  if utilities.is_set ( Scale ) then
   Scale = sepc .. 』" .. Scale;
  end
 end

 -- Account for the oddities that are {{cite episode}} and {{cite serial}}, before generation of COinS data.
 local Series = A['Series'];
 if 'episode' == config.CitationClass or 'serial' == config.CitationClass then
  local SeriesLink = A['SeriesLink'];

  SeriesLink = link_title_ok (SeriesLink, A:ORIGIN ('SeriesLink'), Series, 'series'); -- check for wiki-markup in |series-link= or wiki-markup in |series= when |series-link= is set

  local Network = A['Network'];
  local Station = A['Station'];
  local s, n = {}, {};
                    -- do common parameters first
  if utilities.is_set (Network) then table.insert(n, Network); end
  if utilities.is_set (Station) then table.insert(n, Station); end
  ID = table.concat(n, sepc .. ' ');
  
  if 'episode' == config.CitationClass then        -- handle the oddities that are strictly {{cite episode}}
   local Season = A['Season'];
   local SeriesNumber = A['SeriesNumber'];

   if utilities.is_set (Season) and utilities.is_set (SeriesNumber) then -- these are mutually exclusive so if both are set TODO: make a function for this and similar?
    utilities.set_message ('err_redundant_parameters', {utilities.wrap_style ('parameter', 'season') .. cfg.presentation['sep_list_pair'] .. utilities.wrap_style ('parameter', 'seriesno')});  -- add error message
    SeriesNumber = '';            -- unset; prefer |season= over |seriesno=
   end
                    -- assemble a table of parts concatenated later into Series
   if utilities.is_set (Season) then table.insert(s, wrap_msg ('season', Season, use_lowercase)); end
   if utilities.is_set (SeriesNumber) then table.insert(s, wrap_msg ('seriesnum', SeriesNumber, use_lowercase)); end
   if utilities.is_set (Issue) then table.insert(s, wrap_msg ('episode', Issue, use_lowercase)); end
   Issue = '';               -- unset because this is not a unique parameter
 
   Chapter = Title;             -- promote title parameters to chapter
   ScriptChapter = ScriptTitle;
   ScriptChapter_origin = A:ORIGIN('ScriptTitle');
   ChapterLink = TitleLink;           -- alias |episode-link=
   TransChapter = TransTitle;
   ChapterURL = URL;
   ChapterUrlAccess = UrlAccess;
   ChapterURL_origin = URL_origin;
   ChapterFormat = Format;

   Title = Series;              -- promote series to title
   TitleLink = SeriesLink;
   Series = table.concat(s, sepc .. ' ');        -- this is concatenation of season, seriesno, episode number

   if utilities.is_set (ChapterLink) and not utilities.is_set (ChapterURL) then -- link but not URL
    Chapter = utilities.make_wikilink (ChapterLink, Chapter);
   elseif utilities.is_set (ChapterLink) and utilities.is_set (ChapterURL) then -- if both are set, URL links episode;
    Series = utilities.make_wikilink (ChapterLink, Series);
   end
   URL = '';               -- unset
   TransTitle = '';
   ScriptTitle = '';
   Format = '';
   
  else                 -- now oddities that are cite serial
   Issue = '';               -- unset because this parameter no longer supported by the citation/core version of cite serial
   Chapter = A['Episode'];            -- TODO: make |episode= available to cite episode someday?
   if utilities.is_set (Series) and utilities.is_set (SeriesLink) then
    Series = utilities.make_wikilink (SeriesLink, Series);
   end
   Series = utilities.wrap_style ('italic-title', Series);    -- series is italicized
  end 
 end
 -- end of {{cite episode}} stuff

 -- handle type parameter for those CS1 citations that have default values
 local TitleType = A['TitleType'];
 local Degree = A['Degree'];
 if utilities.in_array (config.CitationClass, {'AV-media-notes', 'document', 'interview', 'mailinglist', 'map', 'podcast', 'pressrelease', 'report', 'speech', 'techreport', 'thesis'}) then
  TitleType = set_titletype (config.CitationClass, TitleType);
  if utilities.is_set (Degree) and "Thesis" == TitleType then    -- special case for cite thesis
   TitleType = Degree .. ' ' .. cfg.title_types ['thesis']:lower();
  end
 end

 if utilities.is_set (TitleType) then          -- if type parameter is specified
  TitleType = utilities.substitute ( cfg.messages['type'], TitleType); -- display it in parentheses
 -- TODO: Hack on TitleType to fix bunched parentheses problem
 end

 -- legacy: promote PublicationDate to Date if neither Date nor Year are set.
 local Date = A['Date'];
  local Date_origin;               -- to hold the name of parameter promoted to Date; required for date error messaging
 local PublicationDate = A['PublicationDate'];
 local Year = A['Year'];

 if not utilities.is_set (Date) then
  Date = Year;               -- promote Year to Date
  Year = nil;                -- make nil so Year as empty string isn't used for CITEREF
  if not utilities.is_set (Date) and utilities.is_set (PublicationDate) then -- use PublicationDate when |date= and |year= are not set
   Date = PublicationDate;            -- promote PublicationDate to Date
   PublicationDate = '';            -- unset, no longer needed
   Date_origin = A:ORIGIN('PublicationDate');       -- save the name of the promoted parameter
  else
   Date_origin = A:ORIGIN('Year');          -- save the name of the promoted parameter
  end
 else
  Date_origin = A:ORIGIN('Date');           -- not a promotion; name required for error messaging
 end

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

 --[[
 Go test all of the date-holding parameters for valid MOS:DATE format and make sure that dates are real dates. This must be done before we do COinS because here is where
 we get the date used in the metadata.
 
 Date validation supporting code is in Module:Citation/CS1/Date_validation
 ]]

 local DF = is_valid_parameter_value (A['DF'], A:ORIGIN('DF'), cfg.keywords_lists['df'], '');
 if not utilities.is_set (DF) then
  DF = cfg.global_df;              -- local |df= if present overrides global df set by {{use xxx date}} template
 end

 local ArchiveURL;
 local ArchiveDate;
 local ArchiveFormat = A['ArchiveFormat'];
 local archive_url_timestamp;            -- timestamp from wayback machine url
 
 ArchiveURL, ArchiveDate, archive_url_timestamp = archive_url_check (A['ArchiveURL'], A['ArchiveDate'])
 ArchiveFormat = style_format (ArchiveFormat, ArchiveURL, 'archive-format', 'archive-url');
 
 ArchiveURL, ArchiveDate = is_unique_archive_url (ArchiveURL, URL, ChapterURL, A:ORIGIN('ArchiveURL'), ArchiveDate);  -- add error message when URL or ChapterURL == ArchiveURL

 local AccessDate = A['AccessDate'];
 local COinS_date = {};              -- holds date info extracted from |date= for the COinS metadata by Module:Date verification
 local DoiBroken = A['DoiBroken'];
 local Embargo = A['Embargo'];
 local anchor_year;               -- used in the CITEREF identifier
 do -- create defined block to contain local variables error_message, date_parameters_list, mismatch
  local error_message = '';
                    -- AirDate has been promoted to Date so not necessary to check it
  local date_parameters_list = {
   ['access-date'] = {val = AccessDate, name = A:ORIGIN ('AccessDate')},
   ['archive-date'] = {val = ArchiveDate, name = A:ORIGIN ('ArchiveDate')},
   ['date'] = {val = Date, name = Date_origin},
   ['doi-broken-date'] = {val = DoiBroken, name = A:ORIGIN ('DoiBroken')},
   ['pmc-embargo-date'] = {val = Embargo, name = A:ORIGIN ('Embargo')},
   ['publication-date'] = {val = PublicationDate, name = A:ORIGIN ('PublicationDate')},
   ['year'] = {val = Year, name = A:ORIGIN ('Year')},
   };

  local error_list = {};
  anchor_year, Embargo = validation.dates(date_parameters_list, COinS_date, error_list);

  if utilities.is_set (Year) and utilities.is_set (Date) then    -- both |date= and |year= not normally needed; 
   validation.year_date_check (Year, A:ORIGIN ('Year'), Date, A:ORIGIN ('Date'), error_list);
  end
  
  if 0 == #error_list then            -- error free dates only; 0 when error_list is empty
   local modified = false;            -- flag
   
   if utilities.is_set (DF) then          -- if we need to reformat dates
    modified = validation.reformat_dates (date_parameters_list, DF); -- reformat to DF format, use long month names if appropriate
   end

   if true == validation.date_hyphen_to_dash (date_parameters_list) then -- convert hyphens to dashes where appropriate
    modified = true;
    utilities.set_message ('maint_date_format');     -- hyphens were converted so add maint category
   end
   
 -- for those wikis that can and want to have English date names translated to the local language; not supported at en.wiki
   if cfg.date_name_auto_xlate_enable and validation.date_name_xlate (date_parameters_list, cfg.date_digit_auto_xlate_enable ) then
    utilities.set_message ('maint_date_auto_xlated');    -- add maint cat
    modified = true;
   end

   if modified then             -- if the date_parameters_list values were modified
    AccessDate = date_parameters_list['access-date'].val;   -- overwrite date holding parameters with modified values
    ArchiveDate = date_parameters_list['archive-date'].val;
    Date = date_parameters_list['date'].val;
    DoiBroken = date_parameters_list['doi-broken-date'].val;
    PublicationDate = date_parameters_list['publication-date'].val;
   end

   if archive_url_timestamp and utilities.is_set (ArchiveDate) then
    validation.archive_date_check (ArchiveDate, archive_url_timestamp, DF); -- does YYYYMMDD in archive_url_timestamp match date in ArchiveDate
   end
  else
   utilities.set_message ('err_bad_date', {utilities.make_sep_list (#error_list, error_list)}); -- add this error message
  end
 end -- end of do

 if utilities.in_array (config.CitationClass, {'book', 'encyclopaedia'}) or -- {{cite book}}, {{cite encyclopedia}}; TODO: {{cite conference}} and others?
  ('citation' == config.CitationClass and utilities.is_set (Encyclopedia)) or   -- {{citation}} as an encylopedia citation
  ('citation' == config.CitationClass and not utilities.is_set (Periodical)) then  -- {{citation}} as a book citation
   if utilities.is_set (PublicationPlace) then
    if not utilities.is_set (PublisherName) then
     local date = COinS_date.rftdate and tonumber (COinS_date.rftdate:match ('%d%d%d%d')); -- get year portion of COinS date (because in Arabic numerals); convert string to number
     if date and (1850 <= date) then        -- location has no publisher; if date is 1850 or later
      utilities.set_message ('maint_location_no_publisher'); -- add maint cat
     end
    else               -- PublisherName has a value
     if cfg.keywords_xlate['none'] == PublisherName then   -- if that value is 'none' (only for book and encyclopedia citations)
      PublisherName = '';          -- unset
     end
    end
   end
 end

 local ID_list = {};               -- sequence table of rendered identifiers
 local ID_list_coins = {};             -- table of identifiers and their values from args; key is same as cfg.id_handlers's key
 local Class = A['Class'];             -- arxiv class identifier
 
 local ID_support = {
  {A['ASINTLD'], 'ASIN', 'err_asintld_missing_asin', A:ORIGIN ('ASINTLD')},    
  {DoiBroken, 'DOI', 'err_doibroken_missing_doi', A:ORIGIN ('DoiBroken')},
  {Embargo, 'PMC', 'err_embargo_missing_pmc', A:ORIGIN ('Embargo')},
  }

 ID_list, ID_list_coins = identifiers.identifier_lists_get (args, {DoiBroken = DoiBroken, ASINTLD = A['ASINTLD'], Embargo = Embargo, Class = Class}, ID_support);

 -- Account for the oddities that are {{cite arxiv}}, {{cite biorxiv}}, {{cite citeseerx}}, {{cite medrxiv}}, {{cite ssrn}}, before generation of COinS data.
 if utilities.in_array (config.CitationClass, whitelist.preprint_template_list_t) then -- |arxiv= or |eprint= required for cite arxiv; |biorxiv=, |citeseerx=, |medrxiv=, |ssrn= required for their templates
  if not (args[cfg.id_handlers[config.CitationClass:upper()].parameters[1]] or   -- can't use ID_list_coins k/v table here because invalid parameters omitted
   args[cfg.id_handlers[config.CitationClass:upper()].parameters[2]]) then   -- which causes unexpected parameter missing error message
    utilities.set_message ('err_' .. config.CitationClass .. '_missing');  -- add error message
  end

  Periodical = ({['arxiv'] = 'arXiv', ['biorxiv'] = 'bioRxiv', ['citeseerx'] = 'CiteSeerX', ['medrxiv'] = 'medRxiv', ['ssrn'] = 'Social Science Research Network'})[config.CitationClass];
 end

 -- Link the title of the work if no |url= was provided, but we have a |pmc= or a |doi= with |doi-access=free

 if config.CitationClass == "journal" and not utilities.is_set (URL) and not utilities.is_set (TitleLink) and not utilities.in_array (cfg.keywords_xlate[Title], {'off', 'none'}) then -- TODO: remove 'none' once existing citations have been switched to 'off', so 'none' can be used as token for "no title" instead
  if 'none' ~= cfg.keywords_xlate[auto_select] then      -- if auto-linking not disabled
     if identifiers.auto_link_urls[auto_select] then      -- manual selection
     URL = identifiers.auto_link_urls[auto_select];     -- set URL to be the same as identifier's external link
     URL_origin = cfg.id_handlers[auto_select:upper()].parameters[1]; -- set URL_origin to parameter name for use in error message if citation is missing a |title=
   elseif identifiers.auto_link_urls['pmc'] then      -- auto-select PMC
    URL = identifiers.auto_link_urls['pmc'];      -- set URL to be the same as the PMC external link if not embargoed
    URL_origin = cfg.id_handlers['PMC'].parameters[1];    -- set URL_origin to parameter name for use in error message if citation is missing a |title=
   elseif identifiers.auto_link_urls['doi'] then      -- auto-select DOI
    URL = identifiers.auto_link_urls['doi'];
    URL_origin = cfg.id_handlers['DOI'].parameters[1];
   end
    end

  if utilities.is_set (URL) then           -- set when using an identifier-created URL
   if utilities.is_set (AccessDate) then        -- |access-date= requires |url=; identifier-created URL is not |url=
    utilities.set_message ('err_accessdate_missing_url');   -- add an error message
    AccessDate = '';            -- unset
   end

   if utilities.is_set (ArchiveURL) then        -- |archive-url= requires |url=; identifier-created URL is not |url=
    utilities.set_message ('err_archive_missing_url');    -- add an error message
    ArchiveURL = '';            -- unset
   end
  end
 end

 -- At this point fields may be nil if they weren't specified in the template use.  We can use that fact.
 -- Test if citation has no title
 if not utilities.is_set (Title) and not utilities.is_set (TransTitle) and not utilities.is_set (ScriptTitle) then -- has special case for cite episode
  utilities.set_message ('err_citation_missing_title', {'episode' == config.CitationClass and 'series' or 'title'});
 end

 if utilities.in_array (cfg.keywords_xlate[Title], {'off', 'none'}) and
   utilities.in_array (config.CitationClass, {'journal', 'citation'}) and
   (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical)) and
   ('journal' == Periodical_origin or 'script-journal' == ScriptPeriodical_origin) then -- special case for journal cites
    Title = '';              -- set title to empty string
    utilities.set_message ('maint_untitled');      -- add maint cat
 end

 -- COinS metadata (see <http://ocoins.info/>) for automated parsing of citation information.
 -- handle the oddity that is cite encyclopedia and {{citation |encyclopedia=something}}. Here we presume that
 -- when Periodical, Title, and Chapter are all set, then Periodical is the book (encyclopedia) title, Title
 -- is the article title, and Chapter is a section within the article.  So, we remap 
 
 local coins_chapter = Chapter;            -- default assuming that remapping not required
 local coins_title = Title;             -- et tu
 if 'encyclopaedia' == config.CitationClass or ('citation' == config.CitationClass and utilities.is_set (Encyclopedia)) then
  if utilities.is_set (Chapter) and utilities.is_set (Title) and utilities.is_set (Periodical) then  -- if all are used then
   coins_chapter = Title;            -- remap
   coins_title = Periodical;
  end
 end
 local coins_author = a;              -- default for coins rft.au 
 if 0 < #c then                -- but if contributor list
  coins_author = c;              -- use that instead
 end
 
 -- this is the function call to COinS()
 local OCinSoutput = metadata.COinS({
  ['Periodical'] = utilities.strip_apostrophe_markup (Periodical),  -- no markup in the metadata
  ['Encyclopedia'] = Encyclopedia,          -- just a flag; content ignored by ~/COinS
  ['Chapter'] = metadata.make_coins_title (coins_chapter, ScriptChapter), -- Chapter and ScriptChapter stripped of bold / italic / accept-as-written markup
  ['Degree'] = Degree;             -- cite thesis only
  ['Title'] = metadata.make_coins_title (coins_title, ScriptTitle),  -- Title and ScriptTitle stripped of bold / italic / accept-as-written markup
  ['PublicationPlace'] = PublicationPlace,
  ['Date'] = COinS_date.rftdate,           -- COinS_date.* has correctly formatted date values if Date is valid;
  ['Season'] = COinS_date.rftssn,
  ['Quarter'] = COinS_date.rftquarter,
  ['Chron'] =  COinS_date.rftchron,
  ['Series'] = Series,
  ['Volume'] = Volume,
  ['Issue'] = Issue,
  ['ArticleNumber'] = ArticleNumber,
  ['Pages'] = coins_pages or metadata.get_coins_pages (first_set ({Sheet, Sheets, Page, Pages, At, QuotePage, QuotePages}, 7)), -- pages stripped of external links
  ['Edition'] = Edition,
  ['PublisherName'] = PublisherName or Newsgroup,       -- any apostrophe markup already removed from PublisherName
  ['URL'] = first_set ({ChapterURL, URL}, 2),
  ['Authors'] = coins_author,
  ['ID_list'] = ID_list_coins,
  ['RawPage'] = this_page.prefixedText,
 }, config.CitationClass);

 -- Account for the oddities that are {{cite arxiv}}, {{cite biorxiv}}, {{cite citeseerx}}, {{cite medrxiv}}, and {{cite ssrn}} AFTER generation of COinS data.
 if utilities.in_array (config.CitationClass, whitelist.preprint_template_list_t) then -- we have set rft.jtitle in COinS to arXiv, bioRxiv, CiteSeerX, medRxiv, or ssrn now unset so it isn't displayed
  Periodical = '';              -- periodical not allowed in these templates; if article has been published, use cite journal
 end

 -- special case for cite newsgroup.  Do this after COinS because we are modifying Publishername to include some static text
 if 'newsgroup' == config.CitationClass and utilities.is_set (Newsgroup) then
  PublisherName = utilities.substitute (cfg.messages['newsgroup'], external_link( 'news:' .. Newsgroup, Newsgroup, Newsgroup_origin, nil ));
 end

 local Editors;
 local EditorCount;               -- used only for choosing {ed.) or (eds.) annotation at end of editor name-list
 local Contributors;               -- assembled contributors name list
 local contributor_etal;
 local Translators;               -- assembled translators name list
 local translator_etal;
 local t = {};                -- translators list from |translator-lastn= / translator-firstn= pairs
 t = extract_names (args, 'TranslatorList');         -- fetch translator list from |translatorn= / |translator-lastn=, -firstn=, -linkn=, -maskn=
 local Interviewers;               
 local interviewers_list = {};     
 interviewers_list = extract_names (args, 'InterviewerList');    -- process preferred interviewers parameters
 local interviewer_etal;
 
 -- Now perform various field substitutions.
 -- We also add leading spaces and surrounding markup and punctuation to the
 -- various parts of the citation, but only when they are non-nil.
 do
  local last_first_list;
  local control = { 
   format = NameListStyle,            -- empty string, '&', 'amp', 'and', or 'vanc'
   maximum = nil,              -- as if display-authors or display-editors not set
   mode = Mode
  };

  do                  -- do editor name list first because the now unsupported coauthors used to modify control table
   local display_names, param = display_names_select (cfg.global_cs1_config_t['DisplayEditors'], A['DisplayEditors'], A:ORIGIN ('DisplayEditors'), #e);
   control.maximum, editor_etal = get_display_names (display_names, #e, 'editors', editor_etal, param);

   Editors, EditorCount = list_people (control, e, editor_etal);

   if 1 == EditorCount and (true == editor_etal or 1 < #e) then  -- only one editor displayed but includes etal then 
    EditorCount = 2;            -- spoof to display (eds.) annotation
   end
  end
  do                  -- now do interviewers
   local display_names, param = display_names_select (cfg.global_cs1_config_t['DisplayInterviewers'], A['DisplayInterviewers'], A:ORIGIN ('DisplayInterviewers'), #interviewers_list);
   control.maximum, interviewer_etal = get_display_names (display_names, #interviewers_list, 'interviewers', interviewer_etal, param);

   Interviewers = list_people (control, interviewers_list, interviewer_etal);
  end
  do                  -- now do translators
   local display_names, param = display_names_select (cfg.global_cs1_config_t['DisplayTranslators'], A['DisplayTranslators'], A:ORIGIN ('DisplayTranslators'), #t);
   control.maximum, translator_etal = get_display_names (display_names, #t, 'translators', translator_etal, param);

   Translators = list_people (control, t, translator_etal);
  end
  do                  -- now do contributors
   local display_names, param = display_names_select (cfg.global_cs1_config_t['DisplayContributors'], A['DisplayContributors'], A:ORIGIN ('DisplayContributors'), #c);
   control.maximum, contributor_etal = get_display_names (display_names, #c, 'contributors', contributor_etal, param);

   Contributors = list_people (control, c, contributor_etal);
  end
  do                  -- now do authors
   local display_names, param = display_names_select (cfg.global_cs1_config_t['DisplayAuthors'], A['DisplayAuthors'], A:ORIGIN ('DisplayAuthors'), #a, author_etal);
   control.maximum, author_etal = get_display_names (display_names, #a, 'authors', author_etal, param);

   last_first_list = list_people (control, a, author_etal);

   if utilities.is_set (Authors) then
    Authors, author_etal = name_has_etal (Authors, author_etal, false, 'authors'); -- find and remove variations on et al.
    if author_etal then
     Authors = Authors .. ' ' .. cfg.messages['et al'];   -- add et al. to authors parameter
    end
   else
    Authors = last_first_list;          -- either an author name list or an empty string
   end
  end                  -- end of do
 
  if utilities.is_set (Authors) and utilities.is_set (Collaboration) then
   Authors = Authors .. ' (' .. Collaboration .. ')';     -- add collaboration after et al.
  end

 end

 local ConferenceFormat = A['ConferenceFormat'];
 local ConferenceURL = A['ConferenceURL'];
 ConferenceFormat = style_format (ConferenceFormat, ConferenceURL, 'conference-format', 'conference-url');
 Format = style_format (Format, URL, 'format', 'url');

 -- special case for chapter format so no error message or cat when chapter not supported
 if not (utilities.in_array (config.CitationClass, {'web', 'news', 'journal', 'magazine', 'pressrelease', 'podcast', 'newsgroup', 'arxiv', 'biorxiv', 'citeseerx', 'medrxiv', 'ssrn'}) or
  ('citation' == config.CitationClass and (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical)) and not utilities.is_set (Encyclopedia))) then
   ChapterFormat = style_format (ChapterFormat, ChapterURL, 'chapter-format', 'chapter-url');
 end

 if not utilities.is_set (URL) then
  if utilities.in_array (config.CitationClass, {"web", "podcast", "mailinglist"}) or  -- |url= required for cite web, cite podcast, and cite mailinglist
   ('citation' == config.CitationClass and ('website' == Periodical_origin or 'script-website' == ScriptPeriodical_origin)) then -- and required for {{citation}} with |website= or |script-website=
    utilities.set_message ('err_cite_web_url');
  end
  
  -- do we have |accessdate= without either |url= or |chapter-url=?
  if utilities.is_set (AccessDate) and not utilities.is_set (ChapterURL) then  -- ChapterURL may be set when URL is not set;
   utilities.set_message ('err_accessdate_missing_url');
   AccessDate = '';
  end
 end

 local UrlStatus = is_valid_parameter_value (A['UrlStatus'], A:ORIGIN('UrlStatus'), cfg.keywords_lists['url-status'], '');
 local OriginalURL
 local OriginalURL_origin
 local OriginalFormat
 local OriginalAccess;
 UrlStatus = UrlStatus:lower();            -- used later when assembling archived text
 if utilities.is_set ( ArchiveURL ) then
  if utilities.is_set (ChapterURL) then          -- if chapter-url= is set apply archive url to it
   OriginalURL = ChapterURL;           -- save copy of source chapter's url for archive text
   OriginalURL_origin = ChapterURL_origin;        -- name of |chapter-url= parameter for error messages
   OriginalFormat = ChapterFormat;          -- and original |chapter-format=

   if 'live' ~= UrlStatus then
    ChapterURL = ArchiveURL           -- swap-in the archive's URL
    ChapterURL_origin = A:ORIGIN('ArchiveURL')      -- name of |archive-url= parameter for error messages
    ChapterFormat = ArchiveFormat or '';       -- swap in archive's format
    ChapterUrlAccess = nil;           -- restricted access levels do not make sense for archived URLs
   end
  elseif utilities.is_set (URL) then
   OriginalURL = URL;             -- save copy of original source URL
   OriginalURL_origin = URL_origin;         -- name of URL parameter for error messages
   OriginalFormat = Format;            -- and original |format=
   OriginalAccess = UrlAccess;

   if 'live' ~= UrlStatus then           -- if URL set then |archive-url= applies to it
    URL = ArchiveURL            -- swap-in the archive's URL
    URL_origin = A:ORIGIN('ArchiveURL')        -- name of archive URL parameter for error messages
    Format = ArchiveFormat or '';         -- swap in archive's format
    UrlAccess = nil;            -- restricted access levels do not make sense for archived URLs
   end
  end
 elseif utilities.is_set (UrlStatus) then         -- if |url-status= is set when |archive-url= is not set
   utilities.set_message ('maint_url_status');        -- add maint cat
 end

 if utilities.in_array (config.CitationClass, {'web', 'news', 'journal', 'magazine', 'pressrelease', 'podcast', 'newsgroup', 'arxiv', 'biorxiv', 'citeseerx', 'medrxiv', 'ssrn'}) or -- if any of the 'periodical' cites except encyclopedia
  ('citation' == config.CitationClass and (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical)) and not utilities.is_set (Encyclopedia)) then
   local chap_param;
   if utilities.is_set (Chapter) then         -- get a parameter name from one of these chapter related meta-parameters
    chap_param = A:ORIGIN ('Chapter')
   elseif utilities.is_set (TransChapter) then
    chap_param = A:ORIGIN ('TransChapter')
   elseif utilities.is_set (ChapterURL) then
    chap_param = A:ORIGIN ('ChapterURL')
   elseif utilities.is_set (ScriptChapter) then
    chap_param = ScriptChapter_origin;
   else utilities.is_set (ChapterFormat)
    chap_param = A:ORIGIN ('ChapterFormat')
   end

   if utilities.is_set (chap_param) then        -- if we found one
    utilities.set_message ('err_chapter_ignored', {chap_param}); -- add error message
    Chapter = '';             -- and set them to empty string to be safe with concatenation
    TransChapter = '';
    ChapterURL = '';
    ScriptChapter = '';
    ChapterFormat = '';
   end
 else                  -- otherwise, format chapter / article title
  local no_quotes = false;            -- default assume that we will be quoting the chapter parameter value
  if utilities.is_set (Contribution) and 0 < #c then      -- if this is a contribution with contributor(s)
   if utilities.in_array (Contribution:lower(), cfg.keywords_lists.contribution) then -- and a generic contribution title
    no_quotes = true;            -- then render it unquoted
   end
  end

  Chapter = format_chapter_title (ScriptChapter, ScriptChapter_origin, Chapter, Chapter_origin, TransChapter, TransChapter_origin, ChapterURL, ChapterURL_origin, no_quotes, ChapterUrlAccess);  -- Contribution is also in Chapter
  if utilities.is_set (Chapter) then
   Chapter = Chapter .. ChapterFormat ;
   if 'map' == config.CitationClass and utilities.is_set (TitleType) then
    Chapter = Chapter .. ' ' .. TitleType;       -- map annotation here; not after title
   end
   Chapter = Chapter .. sepc .. ' ';
  elseif utilities.is_set (ChapterFormat) then       -- |chapter= not set but |chapter-format= is so ...
   Chapter = ChapterFormat .. sepc .. ' ';        -- ... ChapterFormat has error message, we want to see it
  end
 end

 -- Format main title
 local plain_title = false;
 local accept_title;
 Title, accept_title = utilities.has_accept_as_written (Title, true);  -- remove accept-this-as-written markup when it wraps all of <Title>
 if accept_title and ('' == Title) then          -- only support forced empty for now "(())"
  Title = cfg.messages['notitle'];          -- replace by predefined "No title" message
   -- TODO: utilities.set_message ( 'err_redundant_parameters', ...); -- issue proper error message instead of muting  
   ScriptTitle = '';             -- just mute for now  
   TransTitle = '';             -- just mute for now
   plain_title = true;              -- suppress text decoration for descriptive title
  utilities.set_message ('maint_untitled');        -- add maint cat
 end

 if not accept_title then             -- <Title> not wrapped in accept-as-written markup
  if '...' == Title:sub (-3) then           -- if ellipsis is the last three characters of |title=
   Title = Title:gsub ('(%.%.%.)%.+$', '%1');       -- limit the number of dots to three
  elseif not mw.ustring.find (Title, '%.%s*%a%.$') and     -- end of title is not a 'dot-(optional space-)letter-dot' initialism ...
   not mw.ustring.find (Title, '%s+%a%.$') then      -- ...and not a 'space-letter-dot' initial (''Allium canadense'' L.)
    Title = mw.ustring.gsub(Title, '%' .. sepc .. '$', '');   -- remove any trailing separator character; sepc and ms.ustring() here for languages that use multibyte separator characters
  end

  if utilities.is_set (ArchiveURL) and is_archived_copy (Title) then
   utilities.set_message ('maint_archived_copy');      -- add maintenance category before we modify the content of Title
  end

  if is_generic ('generic_titles', Title) then
   utilities.set_message ('err_generic_title');      -- set an error message
  end
 end

 if (not plain_title) and (utilities.in_array (config.CitationClass, {'web', 'news', 'journal', 'magazine', 'document', 'pressrelease', 'podcast', 'newsgroup', 'mailinglist', 'interview', 'arxiv', 'biorxiv', 'citeseerx', 'medrxiv', 'ssrn'}) or
  ('citation' == config.CitationClass and (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical)) and not utilities.is_set (Encyclopedia)) or
  ('map' == config.CitationClass and (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical)))) then  -- special case for cite map when the map is in a periodical treat as an article
   Title = kern_quotes (Title);          -- if necessary, separate title's leading and trailing quote marks from module provided quote marks
   Title = utilities.wrap_style ('quoted-title', Title);
   Title = script_concatenate (Title, ScriptTitle, 'script-title'); -- <bdi> tags, lang attribute, categorization, etc.; must be done after title is wrapped
   TransTitle = utilities.wrap_style ('trans-quoted-title', TransTitle );
 elseif plain_title or ('report' == config.CitationClass) then    -- no styling for cite report and descriptive titles (otherwise same as above)
  Title = script_concatenate (Title, ScriptTitle, 'script-title');  -- <bdi> tags, lang attribute, categorization, etc.; must be done after title is wrapped
  TransTitle = utilities.wrap_style ('trans-quoted-title', TransTitle ); -- for cite report, use this form for trans-title
 else
  Title = utilities.wrap_style ('italic-title', Title);
  Title = script_concatenate (Title, ScriptTitle, 'script-title');  -- <bdi> tags, lang attribute, categorization, etc.; must be done after title is wrapped
  TransTitle = utilities.wrap_style ('trans-italic-title', TransTitle);
 end

 if utilities.is_set (TransTitle) then
  if utilities.is_set (Title) then
   TransTitle = " " .. TransTitle;
  else
   utilities.set_message ('err_trans_missing_title', {'title'});
  end
 end

 if utilities.is_set (Title) then           -- TODO: is this the right place to be making Wikisource URLs?
  if utilities.is_set (TitleLink) and utilities.is_set (URL) then
   utilities.set_message ('err_wikilink_in_url');      -- set an error message because we can't have both
   TitleLink = '';              -- unset
  end
 
  if not utilities.is_set (TitleLink) and utilities.is_set (URL) then
   Title = external_link (URL, Title, URL_origin, UrlAccess) .. TransTitle .. Format;
   URL = '';               -- unset these because no longer needed
   Format = "";
  elseif utilities.is_set (TitleLink) and not utilities.is_set (URL) then
   local ws_url;
   ws_url = wikisource_url_make (TitleLink);       -- ignore ws_label return; not used here
   if ws_url then
    Title = external_link (ws_url, Title .. '&nbsp;', 'ws link in title-link'); -- space char after Title to move icon away from italic text; TODO: a better way to do this?
    Title = utilities.substitute (cfg.presentation['interwiki-icon'], {cfg.presentation['class-wikisource'], TitleLink, Title});    
    Title = Title .. TransTitle;
   else
    Title = utilities.make_wikilink (TitleLink, Title) .. TransTitle;
   end
  else
   local ws_url, ws_label, L;           -- Title has italic or quote markup by the time we get here which causes is_wikilink() to return 0 (not a wikilink)
   ws_url, ws_label, L = wikisource_url_make (Title:gsub('^[\'"]*(.-)[\'"]*$', '%1')); -- make ws URL from |title= interwiki link (strip italic or quote markup); link portion L becomes tooltip label
   if ws_url then
    Title = Title:gsub ('%b[]', ws_label);       -- replace interwiki link with ws_label to retain markup
    Title = external_link (ws_url, Title .. '&nbsp;', 'ws link in title'); -- space char after Title to move icon away from italic text; TODO: a better way to do this?
    Title = utilities.substitute (cfg.presentation['interwiki-icon'], {cfg.presentation['class-wikisource'], L, Title});    
    Title = Title .. TransTitle;
   else
    Title = Title .. TransTitle;
   end
  end
 else
  Title = TransTitle;
 end

 if utilities.is_set (Place) then
  Place = " " .. wrap_msg ('written', Place, use_lowercase) .. sepc .. "『;
 end

 local ConferenceURL_origin = A:ORIGIN('ConferenceURL');      -- get name of parameter that holds ConferenceURL
 if utilities.is_set (Conference) then
  if utilities.is_set (ConferenceURL) then
   Conference = external_link( ConferenceURL, Conference, ConferenceURL_origin, nil );
  end
  Conference = sepc .. 』" .. Conference .. ConferenceFormat;
 elseif utilities.is_set (ConferenceURL) then
  Conference = sepc .. "『 .. external_link( ConferenceURL, nil, ConferenceURL_origin, nil );
 end

 local Position = '';
 if not utilities.is_set (Position) then
  local Minutes = A['Minutes'];
  local Time = A['Time'];

  if utilities.is_set (Minutes) then
   if utilities.is_set (Time) then  --TODO: make a function for this and similar?
    utilities.set_message ('err_redundant_parameters', {utilities.wrap_style ('parameter', 'minutes') .. cfg.presentation['sep_list_pair'] .. utilities.wrap_style ('parameter', 'time')});
   end
   Position = 』" .. Minutes .. "『 .. cfg.messages['minutes'];
  else
   if utilities.is_set (Time) then
    local TimeCaption = A['TimeCaption']
    if not utilities.is_set (TimeCaption) then
     TimeCaption = cfg.messages['event'];
     if sepc ~= '.' then
      TimeCaption = TimeCaption:lower();
     end
    end
    Position = 』" .. TimeCaption .. "『 .. Time;
   end
  end
 else
  Position = 』" .. Position;
  At = '';
 end

 Page, Pages, Sheet, Sheets = format_pages_sheets (Page, Pages, Sheet, Sheets, config.CitationClass, Periodical_origin, sepc, NoPP, use_lowercase);

 At = utilities.is_set (At) and (sepc .. " " .. At) or "";
 Position = utilities.is_set (Position) and (sepc .. " " .. Position) or "";
 if config.CitationClass == 'map' then
  local Sections = A['Sections'];           -- Section (singular) is an alias of Chapter so set earlier
  local Inset = A['Inset'];
  
  if utilities.is_set ( Inset ) then
   Inset = sepc .. "『 .. wrap_msg ('inset', Inset, use_lowercase);
  end   

  if utilities.is_set ( Sections ) then
   Section = sepc .. 』" .. wrap_msg ('sections', Sections, use_lowercase);
  elseif utilities.is_set ( Section ) then
   Section = sepc .. " " .. wrap_msg ('section', Section, use_lowercase);
  end
  At = At .. Inset .. Section;  
 end 

 local Others = A['Others'];
 if utilities.is_set (Others) and 0 == #a and 0 == #e then     -- add maint cat when |others= has value and used without |author=, |editor=
  if config.CitationClass == "AV-media-notes"
  or config.CitationClass == "audio-visual" then       -- special maint for AV/M which has a lot of 'false' positives right now
   utilities.set_message ('maint_others_avm')
  else
   utilities.set_message ('maint_others');
  end
 end
 Others = utilities.is_set (Others) and (sepc .. " " .. Others) or "";
 
 if utilities.is_set (Translators) then
  Others = safe_join ({sepc .. ' ', wrap_msg ('translated', Translators, use_lowercase), Others}, sepc);
 end
 if utilities.is_set (Interviewers) then
  Others = safe_join ({sepc .. ' ', wrap_msg ('interview', Interviewers, use_lowercase), Others}, sepc);
 end
 
 local TitleNote = A['TitleNote'];
 TitleNote = utilities.is_set (TitleNote) and (sepc .. " " .. TitleNote) or "";
 if utilities.is_set (Edition) then
  if Edition:match ('%f[%a][Ee]d%n?%.?$') or Edition:match ('%f[%a][Ee]dition$') then -- Ed, ed, Ed., ed., Edn, edn, Edn., edn.
   utilities.set_message ('err_extra_text_edition');      -- add error message
  end
  Edition = " " .. wrap_msg ('edition', Edition);
 else
  Edition = '';
 end

 Series = utilities.is_set (Series) and wrap_msg ('series', {sepc, Series}) or ""; -- not the same as SeriesNum
 local Agency = A['Agency'] or '';           -- |agency= only supported in {{cite news}}, {{cite press release}}, {{cite web}} and certain {{citation}} templates
 if utilities.is_set (Agency) then           -- this testing done here because {{citation}} supports 'news' citations
  if utilities.in_array (config.CitationClass, {'news', 'pressrelease', 'web'}) or ('citation' == config.CitationClass and utilities.in_array (Periodical_origin, {"newspaper", "work"})) then
   Agency = wrap_msg ('agency', {sepc, Agency});      -- format for rendering
  else
   Agency = '';              -- unset; not supported
   utilities.set_message ('err_parameter_ignored', {'agency'});  -- add error message
  end
 end
 
 Volume = format_volume_issue (Volume, Issue, ArticleNumber, config.CitationClass, Periodical_origin, sepc, use_lowercase);

 if utilities.is_set (AccessDate) then
  local retrv_text = " " .. cfg.messages['retrieved']

  AccessDate = nowrap_date (AccessDate);         -- wrap in nowrap span if date in appropriate format
  if (sepc ~= ".") then retrv_text = retrv_text:lower() end    -- if mode is cs2, lower case
  AccessDate = utilities.substitute (retrv_text, AccessDate);    -- add retrieved text

  AccessDate = utilities.substitute (cfg.presentation['accessdate'], {sepc, AccessDate}); -- allow editors to hide accessdates
 end
 
 if utilities.is_set (ID) then ID = sepc .. " " .. ID; end
 
 local Docket = A['Docket'];
    if "thesis" == config.CitationClass and utilities.is_set (Docket) then
  ID = sepc .. " Docket " .. Docket .. ID;
 end
    if "report" == config.CitationClass and utilities.is_set (Docket) then  -- for cite report when |docket= is set
  ID = sepc .. ' ' .. Docket;            -- overwrite ID even if |id= is set
 end

 if utilities.is_set (URL) then
  URL = " " .. external_link( URL, nil, URL_origin, UrlAccess );
 end

 local Quote = A['Quote'];
 local TransQuote = A['TransQuote'];
 local ScriptQuote = A['ScriptQuote'];
 if utilities.is_set (Quote) or utilities.is_set (TransQuote) or utilities.is_set (ScriptQuote) then

  if utilities.is_set (Quote) then
   if Quote:sub(1, 1) == '"' and Quote:sub(-1, -1) == '"' then   -- if first and last characters of quote are quote marks
    Quote = Quote:sub(2, -2);          -- strip them off
   end
  end
  
  Quote = kern_quotes (Quote);           -- kern if needed
  Quote = utilities.wrap_style ('quoted-text', Quote );     -- wrap in <q>...</q> tags
 
  if utilities.is_set (ScriptQuote) then
   Quote = script_concatenate (Quote, ScriptQuote, 'script-quote'); -- <bdi> tags, lang attribute, categorization, etc.; must be done after quote is wrapped
  end

  if utilities.is_set (TransQuote) then
   if TransQuote:sub(1, 1) == '"' and TransQuote:sub(-1, -1) == '"' then -- if first and last characters of |trans-quote are quote marks
    TransQuote = TransQuote:sub(2, -2); -- strip them off
   end
   Quote = Quote .. " " .. utilities.wrap_style ('trans-quoted-title', TransQuote );
  end

  if utilities.is_set (QuotePage) or utilities.is_set (QuotePages) then -- add page prefix
   local quote_prefix = '';
   if utilities.is_set (QuotePage) then
    extra_text_in_page_check (QuotePage, 'quote-page');    -- add to maint cat if |quote-page= value begins with what looks like p., pp., etc.
    if not NoPP then
     quote_prefix = utilities.substitute (cfg.messages['p-prefix'], {sepc, QuotePage}), '', '', '';
    else
     quote_prefix = utilities.substitute (cfg.messages['nopp'], {sepc, QuotePage}), '', '', '';
    end
   elseif utilities.is_set (QuotePages) then
    extra_text_in_page_check (QuotePages, 'quote-pages');   -- add to maint cat if |quote-pages= value begins with what looks like p., pp., etc.
    if tonumber(QuotePages) ~= nil and not NoPP then    -- if only digits, assume single page
     quote_prefix = utilities.substitute (cfg.messages['p-prefix'], {sepc, QuotePages}), '', '';
    elseif not NoPP then
     quote_prefix = utilities.substitute (cfg.messages['pp-prefix'], {sepc, QuotePages}), '', '';
    else
     quote_prefix = utilities.substitute (cfg.messages['nopp'], {sepc, QuotePages}), '', '';
    end
   end
                        
   Quote = quote_prefix .. ":『 .. Quote;
  else
   Quote = sepc .. 』" .. Quote;
  end

  PostScript = "";              -- cs1|2 does not supply terminal punctuation when |quote= is set
 end
 
 -- We check length of PostScript here because it will have been nuked by
 -- the quote parameters. We'd otherwise emit a message even if there wasn't
 -- a displayed postscript.
 -- TODO: Should the max size (1) be configurable?
 -- TODO: Should we check a specific pattern?
 if utilities.is_set(PostScript) and mw.ustring.len(PostScript) > 1 then
  utilities.set_message ('maint_postscript')
 end
 
 local Archived;
 if utilities.is_set (ArchiveURL) then
  if not utilities.is_set (ArchiveDate) then        -- ArchiveURL set but ArchiveDate not set
   utilities.set_message ('err_archive_missing_date');     -- emit an error message
   ArchiveURL = '';             -- empty string for concatenation
   ArchiveDate = '';             -- empty string for concatenation
  end
 else              
  if utilities.is_set (ArchiveDate) then         -- ArchiveURL not set but ArchiveDate is set
   utilities.set_message ('err_archive_date_missing_url');    -- emit an error message
   ArchiveURL = '';             -- empty string for concatenation
   ArchiveDate = '';             -- empty string for concatenation
  end
 end

 if utilities.is_set (ArchiveURL) then
  local arch_text;
  if "live" == UrlStatus then
   arch_text = cfg.messages['archived'];
   if sepc ~= "." then arch_text = arch_text:lower() end
   if utilities.is_set (ArchiveDate) then
    Archived = sepc .. ' ' .. utilities.substitute ( cfg.messages['archived-live'],
     {external_link( ArchiveURL, arch_text, A:ORIGIN('ArchiveURL'), nil) .. ArchiveFormat, ArchiveDate } );
   else
    Archived = '';
   end
   if not utilities.is_set (OriginalURL) then
    utilities.set_message ('err_archive_missing_url');
    Archived = '';             -- empty string for concatenation
   end
  elseif utilities.is_set (OriginalURL) then        -- UrlStatus is empty, 'dead', 'unfit', 'usurped', 'bot: unknown'
   if utilities.in_array (UrlStatus, {'unfit', 'usurped', 'bot: unknown'}) then
    arch_text = cfg.messages['archived-unfit'];
    if sepc ~= "." then arch_text = arch_text:lower() end
    Archived = sepc .. ' ' .. arch_text .. ArchiveDate;    -- format already styled
    if 'bot: unknown' == UrlStatus then
     utilities.set_message ('maint_bot_unknown');    -- and add a category if not already added
    else
     utilities.set_message ('maint_unfit');      -- and add a category if not already added
    end
   else                -- UrlStatus is empty, 'dead'
    arch_text = cfg.messages['archived-dead'];
    if sepc ~= "." then arch_text = arch_text:lower() end
    if utilities.is_set (ArchiveDate) then
     Archived = sepc .. "『 .. utilities.substitute ( arch_text,
      { external_link( OriginalURL, cfg.messages['original'], OriginalURL_origin, OriginalAccess ) .. OriginalFormat, ArchiveDate } ); -- format already styled
    else
     Archived = '';            -- unset for concatenation
    end
   end 
  else                 -- OriginalUrl not set
   utilities.set_message ('err_archive_missing_url');
   Archived = '';              -- empty string for concatenation
  end
 elseif utilities.is_set (ArchiveFormat) then
  Archived = ArchiveFormat;            -- if set and ArchiveURL not set ArchiveFormat has error message
 else
  Archived = '';
 end
 
 local TranscriptURL = A['TranscriptURL']
 local TranscriptFormat = A['TranscriptFormat'];
 TranscriptFormat = style_format (TranscriptFormat, TranscriptURL, 'transcript-format', 'transcripturl');
 local Transcript = A['Transcript'];
 local TranscriptURL_origin = A:ORIGIN('TranscriptURL');      -- get name of parameter that holds TranscriptURL
 if utilities.is_set (Transcript) then
  if utilities.is_set (TranscriptURL) then
   Transcript = external_link( TranscriptURL, Transcript, TranscriptURL_origin, nil );
  end
  Transcript = sepc .. ' ' .. Transcript .. TranscriptFormat;
 elseif utilities.is_set (TranscriptURL) then
  Transcript = external_link( TranscriptURL, nil, TranscriptURL_origin, nil );
 end

 local Publisher;
 if utilities.is_set (PublicationDate) then
  PublicationDate = wrap_msg ('published', PublicationDate);
 end
 if utilities.is_set (PublisherName) then
  if utilities.is_set (PublicationPlace) then
   Publisher = sepc .. 』" .. PublicationPlace .. ":『 .. PublisherName .. PublicationDate;
  else
   Publisher = sepc .. 』" .. PublisherName .. PublicationDate;  
  end   
 elseif utilities.is_set (PublicationPlace) then 
  Publisher= sepc .. "『 .. PublicationPlace .. PublicationDate;
 else 
  Publisher = PublicationDate;
 end
 
 -- Several of the above rely upon detecting this as nil, so do it last.
 if (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical) or utilities.is_set (TransPeriodical)) then
  if utilities.is_set (Title) or utilities.is_set (TitleNote) then 
   Periodical = sepc .. 』" .. format_periodical (ScriptPeriodical, ScriptPeriodical_origin, Periodical, TransPeriodical, TransPeriodical_origin);
  else 
   Periodical = format_periodical (ScriptPeriodical, ScriptPeriodical_origin, Periodical, TransPeriodical, TransPeriodical_origin);
  end
 end
 
 local Language = A['Language'];
 if utilities.is_set (Language) then
  Language = language_parameter (Language);        -- format, categories, name from ISO639-1, etc.
 else
  Language='';               -- language not specified so make sure this is an empty string;
 --[[ TODO: need to extract the wrap_msg from language_parameter
 so that we can solve parentheses bunching problem with Format/Language/TitleType
 ]]
 end

 --[[
 Handle the oddity that is cite speech.  This code overrides whatever may be the value assigned to TitleNote (through |department=) and forces it to be " (Speech)" so that
 the annotation directly follows the |title= parameter value in the citation rather than the |event= parameter value (if provided).
 ]]
 if "speech" == config.CitationClass then         -- cite speech only
  TitleNote = TitleType;             -- move TitleType to TitleNote so that it renders ahead of |event=
  TitleType = '';               -- and unset

  if utilities.is_set (Periodical) then         -- if Periodical, perhaps because of an included |website= or |journal= parameter 
   if utilities.is_set (Conference) then        -- and if |event= is set
    Conference = Conference .. sepc .. " ";       -- then add appropriate punctuation to the end of the Conference variable before rendering
   end
  end
 end

 -- Piece all bits together at last.  Here, all should be non-nil.
 -- We build things this way because it is more efficient in LUA
 -- not to keep reassigning to the same string variable over and over.

 local tcommon;
 local tcommon2;                -- used for book cite when |contributor= is set
 
 if utilities.in_array (config.CitationClass, {"book", "citation"}) and not utilities.is_set (Periodical) then  -- special cases for book cites
  if utilities.is_set (Contributors) then         -- when we are citing foreword, preface, introduction, etc.
   tcommon = safe_join ({Title, TitleNote}, sepc);      -- author and other stuff will come after this and before tcommon2
   tcommon2 = safe_join ({TitleType, Series, Language, Volume, Others, Edition, Publisher}, sepc);
  else
   tcommon = safe_join ({Title, TitleNote, TitleType, Series, Language, Volume, Others, Edition, Publisher}, sepc);
  end

 elseif 'map' == config.CitationClass then         -- special cases for cite map
  if utilities.is_set (Chapter) then          -- map in a book; TitleType is part of Chapter
   tcommon = safe_join ({Title, Edition, Scale, Series, Language, Cartography, Others, Publisher, Volume}, sepc);
  elseif utilities.is_set (Periodical) then        -- map in a periodical
   tcommon = safe_join ({Title, TitleType, Periodical, Scale, Series, Language, Cartography, Others, Publisher, Volume}, sepc);
  else                 -- a sheet or stand-alone map
   tcommon = safe_join ({Title, TitleType, Edition, Scale, Series, Language, Cartography, Others, Publisher}, sepc);
  end
  
 elseif 'episode' == config.CitationClass then        -- special case for cite episode
  tcommon = safe_join ({Title, TitleNote, TitleType, Series, Language, Edition, Publisher}, sepc);

 else                  -- all other CS1 templates
  tcommon = safe_join ({Title, TitleNote, Conference, Periodical, TitleType, Series, Language, Volume, Others, Edition, Publisher, Agency}, sepc);
 end
 
 if #ID_list > 0 then
  ID_list = safe_join( { sepc .. " ",  table.concat( ID_list, sepc .. "『 ), ID }, sepc );
 else
  ID_list = ID;
 end
 
 local Via = A['Via'];
 Via = utilities.is_set (Via) and  wrap_msg ('via', Via) or '';
 local idcommon;
 if 'audio-visual' == config.CitationClass or 'episode' == config.CitationClass then -- special case for cite AV media & cite episode position transcript
  idcommon = safe_join( { ID_list, URL, Archived, Transcript, AccessDate, Via, Quote }, sepc );
 else
  idcommon = safe_join( { ID_list, URL, Archived, AccessDate, Via, Quote }, sepc );
 end
 
 local text;
 local pgtext = Position .. Sheet .. Sheets .. Page .. Pages .. At;

 local OrigDate = A['OrigDate'];
 OrigDate = utilities.is_set (OrigDate) and wrap_msg ('origdate', OrigDate) or '';
 if utilities.is_set (Date) then
  if utilities.is_set (Authors) or utilities.is_set (Editors) then  -- date follows authors or editors when authors not set
   Date = 』(" .. Date .. ")" .. OrigDate .. sepc .. "『;    -- in parentheses
  else                 -- neither of authors and editors set
   if (string.sub(tcommon, -1, -1) == sepc) then      -- if the last character of tcommon is sepc
    Date = 』" .. Date .. OrigDate;         -- Date does not begin with sepc
   else
    Date = sepc .. "『 .. Date .. OrigDate;       -- Date begins with sepc
   end
  end
 end 
 if utilities.is_set (Authors) then
  if (not utilities.is_set (Date)) then         -- when date is set it's in parentheses; no Authors termination
   Authors = terminate_name_list (Authors, sepc);      -- when no date, terminate with 0 or 1 sepc and a space
  end
  if utilities.is_set (Editors) then
   local in_text = '';
   local post_text = '';
   if utilities.is_set (Chapter) and 0 == #c then
    in_text = cfg.messages['in'] .. ' ';
    if (sepc ~= '.') then
     in_text = in_text:lower();         -- lowercase for cs2
    end
   end
   if EditorCount <= 1 then
    post_text = ' (' .. cfg.messages['editor'] .. ')';    -- be consistent with no-author, no-date case
   else
    post_text = ' (' .. cfg.messages['editors'] .. ')';
   end
   Editors = terminate_name_list (in_text .. Editors .. post_text, sepc); -- terminate with 0 or 1 sepc and a space
  end
  if utilities.is_set (Contributors) then         -- book cite and we're citing the intro, preface, etc.
   local by_text = sepc .. ' ' .. cfg.messages['by'] .. ' ';
   if (sepc ~= '.') then by_text = by_text:lower() end     -- lowercase for cs2
   Authors = by_text .. Authors;          -- author follows title so tweak it here
   if utilities.is_set (Editors) and utilities.is_set (Date) then  -- when Editors make sure that Authors gets terminated
    Authors = terminate_name_list (Authors, sepc);     -- terminate with 0 or 1 sepc and a space
   end
   if (not utilities.is_set (Date)) then        -- when date is set it's in parentheses; no Contributors termination
    Contributors = terminate_name_list (Contributors, sepc);  -- terminate with 0 or 1 sepc and a space
   end
   text = safe_join( {Contributors, Date, Chapter, tcommon, Authors, Place, Editors, tcommon2, pgtext, idcommon }, sepc );
  else
   text = safe_join( {Authors, Date, Chapter, Place, Editors, tcommon, pgtext, idcommon }, sepc );
  end
 elseif utilities.is_set (Editors) then
  if utilities.is_set (Date) then
   if EditorCount <= 1 then
    Editors = Editors .. cfg.presentation['sep_name'] .. cfg.messages['editor'];
   else
    Editors = Editors .. cfg.presentation['sep_name'] .. cfg.messages['editors'];
   end
  else
   if EditorCount <= 1 then
    Editors = Editors .. 』(" .. cfg.messages['editor'] .. ")" .. sepc .. "『
   else
    Editors = Editors .. 』(" .. cfg.messages['editors'] .. ")" .. sepc .. " "
   end
  end
  text = safe_join( {Editors, Date, Chapter, Place, tcommon, pgtext, idcommon}, sepc );
 else
  if utilities.in_array (config.CitationClass, {"journal", "citation"}) and utilities.is_set (Periodical) then
   text = safe_join( {Chapter, Place, tcommon, pgtext, Date, idcommon}, sepc );
  else
   text = safe_join( {Chapter, Place, tcommon, Date, pgtext, idcommon}, sepc );
  end
 end

 if utilities.is_set (PostScript) and PostScript ~= sepc then
  text = safe_join( {text, sepc}, sepc );         -- Deals with italics, spaces, etc.
  if '.' == sepc then              -- remove final seperator if present
   text = text:gsub ('%' .. sepc .. '$', '');       -- dot must be escaped here
  else
   text = mw.ustring.gsub (text, sepc .. '$', '');      -- using ustring for non-dot sepc (likely a non-Latin character)
  end
 end 
 
 text = safe_join( {text, PostScript}, sepc );

 -- Now enclose the whole thing in a <cite> element
 local options_t = {};
 options_t.class = cite_class_attribute_make (config.CitationClass, Mode);

 local Ref = is_valid_parameter_value (A['Ref'], A:ORIGIN('Ref'), cfg.keywords_lists['ref'], nil, true); -- nil when |ref=harv; A['Ref'] else

 if 'none' ~= cfg.keywords_xlate[(Ref and Ref:lower()) or ''] then
  local namelist_t = {};             -- holds selected contributor, author, editor name list
  local year = first_set ({Year, anchor_year}, 2);      -- Year first for legacy citations and for YMD dates that require disambiguation

  if #c > 0 then               -- if there is a contributor list
   namelist_t = c;              -- select it
  elseif #a > 0 then              -- or an author list
   namelist_t = a;
  elseif #e > 0 then              -- or an editor list
   namelist_t = e;
  end
  local citeref_id;
  if #namelist_t > 0 then             -- if there are names in namelist_t
   citeref_id = make_citeref_id (namelist_t, year);     -- go make the CITEREF anchor
   if mw.uri.anchorEncode (citeref_id) == ((Ref and mw.uri.anchorEncode (Ref)) or '') then -- Ref may already be encoded (by {{sfnref}}) so citeref_id must be encoded before comparison
    utilities.set_message ('maint_ref_duplicates_default');
   end
  else
   citeref_id = '';             -- unset
  end
  options_t.id = Ref or citeref_id;
 end

 if string.len (text:gsub('%b<>', '')) <= 2 then        -- remove html and html-like tags; then get length of what remains; 
  z.error_cats_t = {};             -- blank the categories list
  z.error_msgs_t = {};             -- blank the error messages list
  OCinSoutput = nil;              -- blank the metadata string
  text = '';                -- blank the the citation
  utilities.set_message ('err_empty_citation');       -- set empty citation message and category
 end
 
 local render_t = {};              -- here we collect the final bits for concatenation into the rendered citation

 if utilities.is_set (options_t.id) then          -- here we wrap the rendered citation in <cite ...>...</cite> tags
  table.insert (render_t, utilities.substitute (cfg.presentation['cite-id'], {mw.uri.anchorEncode(options_t.id), mw.text.nowiki(options_t.class), text})); -- when |ref= is set or when there is a namelist
 else
  table.insert (render_t, utilities.substitute (cfg.presentation['cite'], {mw.text.nowiki(options_t.class), text})); -- when |ref=none or when namelist_t empty and |ref= is missing or is empty
 end  

 if OCinSoutput then               -- blanked when citation is 'empty' so don't bother to add boilerplate metadata span
  table.insert (render_t, utilities.substitute (cfg.presentation['ocins'], OCinSoutput)); -- format and append metadata to the citation
 end

 local template_name = ('citation' == config.CitationClass) and 'citation' or 'cite ' .. (cfg.citation_class_map_t[config.CitationClass] or config.CitationClass);
 local template_link = '[[Template:' .. template_name .. '|' .. template_name .. ']]';
 local msg_prefix = '<code class="cs1-code">{{' .. template_link .. '}}</code>: ';

 if 0 ~= #z.error_msgs_t then
  mw.addWarning (utilities.substitute (cfg.messages.warning_msg_e, template_link));

  table.insert (render_t, ' ');           -- insert a space between citation and its error messages
  table.sort (z.error_msgs_t);           -- sort the error messages list; sorting includes wrapping <span> and <code> tags; hidden-error sorts ahead of visible-error

  local hidden = true;             -- presume that the only error messages emited by this template are hidden
  for _, v in ipairs (z.error_msgs_t) do         -- spin through the list of error messages
   if v:find ('cs1-visible-error', 1, true) then      -- look for the visible error class name
    hidden = false;             -- found one; so don't hide the error message prefix
    break;               -- and done because no need to look further
   end
  end

  z.error_msgs_t[1] = table.concat ({utilities.error_comment (msg_prefix, hidden), z.error_msgs_t[1]}); -- add error message prefix to first error message to prevent extraneous punctuation
  table.insert (render_t, table.concat (z.error_msgs_t, '; '));   -- make a big string of error messages and add it to the rendering
 end

 if 0 ~= #z.maint_cats_t then
  mw.addWarning (utilities.substitute (cfg.messages.warning_msg_m, template_link));

  table.sort (z.maint_cats_t);           -- sort the maintenance messages list

  local maint_msgs_t = {};            -- here we collect all of the maint messages

  if 0 == #z.error_msgs_t then           -- if no error messages
   table.insert (maint_msgs_t, msg_prefix);       -- insert message prefix in maint message livery
  end
  
  for _, v in ipairs( z.maint_cats_t ) do         -- append maintenance categories
   table.insert (maint_msgs_t,           -- assemble new maint message and add it to the maint_msgs_t table
    table.concat ({v, ' (', utilities.substitute (cfg.messages[':cat wikilink'], v), ')'})
    );
  end
  table.insert (render_t, utilities.substitute (cfg.presentation['hidden-maint'], table.concat (maint_msgs_t, ' '))); -- wrap the group of maint messages with proper presentation and save
 end

 if not no_tracking_cats then
  local sort_key;
  local cat_wikilink = 'cat wikilink';
  if cfg.enable_sort_keys then           -- when namespace sort keys enabled
   local namespace_number = mw.title.getCurrentTitle().namespace;  -- get namespace number for this wikitext
   sort_key = (0 ~= namespace_number and (cfg.name_space_sort_keys[namespace_number] or cfg.name_space_sort_keys.other)) or nil; -- get sort key character; nil for mainspace
   cat_wikilink = (not sort_key and 'cat wikilink') or 'cat wikilink sk'; -- make <cfg.messages> key
  end    

  for _, v in ipairs (z.error_cats_t) do         -- append error categories
   table.insert (render_t, utilities.substitute (cfg.messages[cat_wikilink], {v, sort_key}));
  end
  for _, v in ipairs (z.maint_cats_t) do         -- append maintenance categories
   table.insert (render_t, utilities.substitute (cfg.messages[cat_wikilink], {v, sort_key}));
  end

  for _, v in ipairs (z.prop_cats_t) do         -- append properties categories
   table.insert (render_t, utilities.substitute (cfg.messages['cat wikilink'], v)); -- no sort keys
  end
 end

 return table.concat (render_t);            -- make a big string and done
end


--[[--------------------------< V A L I D A T E >--------------------------------------------------------------

Looks for a parameter's name in one of several whitelists.

Parameters in the whitelist can have three values:
 true - active, supported parameters
 false - deprecated, supported parameters
 nil - unsupported parameters
 
]]

local function validate (name, cite_class, empty)
 local name = tostring (name);
 local enum_name;               -- parameter name with enumerator (if any) replaced with '#'
 local state;
 local function state_test (state, name)          -- local function to do testing of state values
  if true == state then return true; end         -- valid actively supported parameter
  if false == state then
   if empty then return nil; end          -- empty deprecated parameters are treated as unknowns
   deprecated_parameter (name);          -- parameter is deprecated but still supported
   return true;
  end
  if 'tracked' == state then
   local base_name = name:gsub ('%d', '');        -- strip enumerators from parameter names that have them to get the base name
   utilities.add_prop_cat ('tracked-param', {base_name}, base_name); -- add a properties category; <base_name> modifies <key>
   return true;
  end
  return nil;
 end  

 if name:find ('#') then              -- # is a cs1|2 reserved character so parameters with # not permitted
  return nil;
 end
                    -- replace enumerator digit(s) with # (|last25= becomes |last#=) (mw.ustring because non-Western 'local' digits)
 enum_name = mw.ustring.gsub (name, '%d+$', '#');       -- where enumerator is last charaters in parameter name (these to protect |s2cid=)
 enum_name = mw.ustring.gsub (enum_name, '%d+([%-l])', '#%1');    -- where enumerator is in the middle of the parameter name; |author#link= is the oddity

 if 'document' == cite_class then           -- special case for {{cite document}}
  state = whitelist.document_parameters_t[enum_name];      -- this list holds enumerated and nonenumerated parameters
  if true == state_test (state, name) then return true; end
  
  return false;
 end

 if utilities.in_array (cite_class, whitelist.preprint_template_list_t) then -- limited parameter sets allowed for these templates
  state = whitelist.limited_parameters_t[enum_name];      -- this list holds enumerated and nonenumerated parameters
  if true == state_test (state, name) then return true; end

  state = whitelist.preprint_arguments_t[cite_class][name];    -- look in the parameter-list for the template identified by cite_class
  if true == state_test (state, name) then return true; end

  return false;               -- not supported because not found or name is set to nil
 end                   -- end limited parameter-set templates

 if utilities.in_array (cite_class, whitelist.unique_param_template_list_t) then  -- template-specific parameters for templates that accept parameters from the basic argument list
  state = whitelist.unique_arguments_t[cite_class][name];     -- look in the template-specific parameter-lists for the template identified by cite_class
  if true == state_test (state, name) then return true; end
 end                   -- if here, fall into general validation

 state = whitelist.common_parameters_t[enum_name];       -- all other templates; all normal parameters allowed; this list holds enumerated and nonenumerated parameters
 if true == state_test (state, name) then return true; end

 return false;                -- not supported because not found or name is set to nil
end


--[=[-------------------------< I N T E R _ W I K I _ C H E C K >----------------------------------------------

check <value> for inter-language interwiki-link markup.  <prefix> must be a MediaWiki-recognized language
code.  when these values have the form (without leading colon):
 [[<prefix>:link|label]] return label as plain-text
 [[<prefix>:link]] return <prefix>:link as plain-text

return value as is else

]=]

local function inter_wiki_check (parameter, value)
 local prefix = value:match ('%[%[(%a+):');         -- get an interwiki prefix if one exists
 local _;
 
 if prefix and cfg.inter_wiki_map[prefix:lower()] then      -- if prefix is in the map, needs preceding colon so
  utilities.set_message ('err_bad_paramlink', parameter);     -- emit an error message
  _, value, _ = utilities.is_wikilink (value);       -- extract label portion from wikilink
 end
 return value;
end


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

Look at the contents of a parameter. If the content has a string of characters and digits followed by an equal
sign, compare the alphanumeric string to the list of cs1|2 parameters.  If found, then the string is possibly a
parameter that is missing its pipe.  There are two tests made:
 {{cite ... |title=Title access-date=2016-03-17}} -- the first parameter has a value and whitespace separates that value from the missing pipe parameter name
 {{cite ... |title=access-date=2016-03-17}}   -- the first parameter has no value (whitespace after the first = is trimmed by MediaWiki)
cs1|2 shares some parameter names with XML/HTML attributes: class=, title=, etc.  To prevent false positives XML/HTML
tags are removed before the search.

If a missing pipe is detected, this function adds the missing pipe maintenance category.

]]

local function missing_pipe_check (parameter, value)
 local capture;
 value = value:gsub ('%b<>', '');           -- remove XML/HTML tags because attributes: class=, title=, etc.

 capture = value:match ('%s+(%a[%w%-]+)%s*=') or value:match ('^(%a[%w%-]+)%s*='); -- find and categorize parameters with possible missing pipes
 if capture and validate (capture) then          -- if the capture is a valid parameter name
  utilities.set_message ('err_missing_pipe', parameter);
 end
end


--[[--------------------------< H A S _ E X T R A N E O U S _ P U N C T >--------------------------------------

look for extraneous terminal punctuation in most parameter values; parameters listed in skip table are not checked

]]

local function has_extraneous_punc (param, value)
 if 'number' == type (param) then
  return;
 end
 
 param = param:gsub ('%d+', '#');           -- enumerated name-list mask params allow terminal punct; normalize 
 if cfg.punct_skip[param] then
  return;                 -- parameter name found in the skip table so done
 end
 
 if value:match ('[,;:]$') then
  utilities.set_message ('maint_extra_punct');       -- has extraneous punctuation; add maint cat
 end
 if value:match ('^=') then             -- sometimes an extraneous '=' character appears ...
  utilities.set_message ('maint_extra_punct');       -- has extraneous punctuation; add maint cat
 end
end


--[[--------------------------< H A S _ E X T R A N E O U S _ U R L >------------------------------------------

look for extraneous url parameter values; parameters listed in skip table are not checked

]]

local function has_extraneous_url (url_param_t)
 local url_error_t = {};
 
 check_for_url (url_param_t, url_error_t);         -- extraneous url check
 if 0 ~= #url_error_t then             -- non-zero when there are errors
  table.sort (url_error_t);
  utilities.set_message ('err_param_has_ext_link', {utilities.make_sep_list (#url_error_t, url_error_t)}); -- add this error message
 end
end


--[[--------------------------< C I T A T I O N >--------------------------------------------------------------

This is used by templates such as {{cite book}} to create the actual citation text.

]]

local function citation(frame)
 Frame = frame;                -- save a copy in case we need to display an error message in preview mode

 local config = {};               -- table to store parameters from the module {{#invoke:}}
 for k, v in pairs( frame.args ) do           -- get parameters from the {{#invoke}} frame
  config[k] = v;
 -- args[k] = v;               -- crude debug support that allows us to render a citation from module {{#invoke:}}; skips parameter validation; TODO: keep?
 end 
                    -- i18n: set the name that your wiki uses to identify sandbox subpages from sandbox template invoke (or can be set here)
 local sandbox = ((config.SandboxPath and '' ~= config.SandboxPath) and config.SandboxPath) or '/sandbox'; -- sandbox path from {{#invoke:Citation/CS1/sandbox|citation|SandboxPath=/...}}
 is_sandbox = nil ~= string.find (frame:getTitle(), sandbox, 1, true);  -- is this invoke the sandbox module?
 sandbox = is_sandbox and sandbox or '';          -- use i18n sandbox to load sandbox modules when this module is the sandox; live modules else

 local pframe = frame:getParent()
 local styles;
 
 cfg = mw.loadData ('Module:Citation/CS1/Configuration' .. sandbox);   -- load sandbox versions of support modules when {{#invoke:Citation/CS1/sandbox|...}}; live modules else
 whitelist = mw.loadData ('Module:Citation/CS1/Whitelist' .. sandbox);
 utilities = require ('Module:Citation/CS1/Utilities' .. sandbox);
 validation = require ('Module:Citation/CS1/Date_validation' .. sandbox);
 identifiers = require ('Module:Citation/CS1/Identifiers' .. sandbox);
 metadata = require ('Module:Citation/CS1/COinS' .. sandbox);
 styles = 'Module:Citation/CS1' .. sandbox .. '/styles.css';

 utilities.set_selected_modules (cfg);          -- so that functions in Utilities can see the selected cfg tables
 identifiers.set_selected_modules (cfg, utilities);       -- so that functions in Identifiers can see the selected cfg tables and selected Utilities module
 validation.set_selected_modules (cfg, utilities);       -- so that functions in Date validataion can see selected cfg tables and the selected Utilities module
 metadata.set_selected_modules (cfg, utilities);        -- so that functions in COinS can see the selected cfg tables and selected Utilities module

 z = utilities.z;               -- table of error and category tables in Module:Citation/CS1/Utilities

 is_preview_mode = not utilities.is_set (frame:preprocess ('{{REVISIONID}}'));

 local args = {};               -- table where we store all of the template's arguments
 local suggestions = {};              -- table where we store suggestions if we need to loadData them
 local error_text;               -- used as a flag

 local capture;                -- the single supported capture when matching unknown parameters using patterns
 local empty_unknowns = {};             -- sequence table to hold empty unknown params for error message listing
 for k, v in pairs( pframe.args ) do           -- get parameters from the parent (template) frame
  v = mw.ustring.gsub (v, '^%s*(.-)%s*$', '%1');       -- trim leading/trailing whitespace; when v is only whitespace, becomes empty string
  if v ~= '' then
   if ('string' == type (k)) then
    k = mw.ustring.gsub (k, '%d', cfg.date_names.local_digits);  -- for enumerated parameters, translate 'local' digits to Western 0-9
   end
   if not validate( k, config.CitationClass ) then   
    if type (k) ~= 'string' then         -- exclude empty numbered parameters
     if v:match("%S+") ~= nil then
      error_text = utilities.set_message ('err_text_ignored', {v});
     end
    elseif validate (k:lower(), config.CitationClass) then 
     error_text = utilities.set_message ('err_parameter_ignored_suggest', {k, k:lower()}); -- suggest the lowercase version of the parameter
    else
     if nil == suggestions.suggestions then      -- if this table is nil then we need to load it
      suggestions = mw.loadData ('Module:Citation/CS1/Suggestions' .. sandbox); --load sandbox version of suggestion module when {{#invoke:Citation/CS1/sandbox|...}}; live module else
     end
     for pattern, param in pairs (suggestions.patterns) do  -- loop through the patterns to see if we can suggest a proper parameter
      capture = k:match (pattern);       -- the whole match if no capture in pattern else the capture if a match
      if capture then           -- if the pattern matches 
       param = utilities.substitute (param, capture);  -- add the capture to the suggested parameter (typically the enumerator)
       if validate (param, config.CitationClass) then  -- validate the suggestion to make sure that the suggestion is supported by this template (necessary for limited parameter lists)
        error_text = utilities.set_message ('err_parameter_ignored_suggest', {k, param}); -- set the suggestion error message
       else
        error_text = utilities.set_message ('err_parameter_ignored', {k}); -- suggested param not supported by this template
        v = '';           -- unset
       end
      end
     end
     if not utilities.is_set (error_text) then     -- couldn't match with a pattern, is there an explicit suggestion?      
      if (suggestions.suggestions[ k:lower() ] ~= nil) and validate (suggestions.suggestions[ k:lower() ], config.CitationClass) then
       utilities.set_message ('err_parameter_ignored_suggest', {k, suggestions.suggestions[ k:lower() ]});
      else
       utilities.set_message ('err_parameter_ignored', {k});
       v = '';            -- unset value assigned to unrecognized parameters (this for the limited parameter lists)
      end
     end
    end      
   end

   args[k] = v;              -- save this parameter and its value

  elseif not utilities.is_set (v) then         -- for empty parameters
   if not validate (k, config.CitationClass, true) then    -- is this empty parameter a valid parameter
    k = ('' == k) and '(empty string)' or k;      -- when k is empty string (or was space(s) trimmed to empty string), replace with descriptive text
    table.insert (empty_unknowns, utilities.wrap_style ('parameter', k)); -- format for error message and add to the list
   end
                    -- crude debug support that allows us to render a citation from module {{#invoke:}} TODO: keep?
 -- elseif args[k] ~= nil or (k == 'postscript') then      -- when args[k] has a value from {{#invoke}} frame (we don't normally do that)
 --  args[k] = v;              -- overwrite args[k] with empty string from pframe.args[k] (template frame); v is empty string here
  end                  -- not sure about the postscript bit; that gets handled in parameter validation; historical artifact?
 end 

 if 0 ~= #empty_unknowns then            -- create empty unknown error message
  utilities.set_message ('err_param_unknown_empty', {
   1 == #empty_unknowns and '' or 's',
   utilities.make_sep_list (#empty_unknowns, empty_unknowns)
   });
 end

 local url_param_t = {};

 for k, v in pairs( args ) do
  if 'string' == type (k) then           -- don't evaluate positional parameters
   has_invisible_chars (k, v);           -- look for invisible characters
  end
  has_extraneous_punc (k, v);            -- look for extraneous terminal punctuation in parameter values
  missing_pipe_check (k, v);            -- do we think that there is a parameter that is missing a pipe?
  args[k] = inter_wiki_check (k, v);          -- when language interwiki-linked parameter missing leading colon replace with wiki-link label

  if 'string' == type (k) and not cfg.url_skip[k] then     -- when parameter k is not positional and not in url skip table
   url_param_t[k] = v;             -- make a parameter/value list for extraneous url check
  end
 end

 has_extraneous_url (url_param_t);           -- look for url in parameter values where a url does not belong

 return table.concat ({
  frame:extensionTag ('templatestyles', '', {src=styles}),
  citation0( config, args)
 });
end


--[[--------------------------< E X P O R T E D   F U N C T I O N S >------------------------------------------
]]

return {citation = citation};

Retrieved from "https://en.wikipedia.org/w/index.php?title=Module:Citation/CS1&oldid=1215172432"

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This page was last edited on 23 March 2024, at 15:32 (UTC).

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