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    Module:Citation/CS1/doc: Difference between revisions

    Content added Content deleted
    VisualWikitext
    (Created page with "require ('Module:No globals'); --[[--------------------------< F O R W A R D D E C L A R A T I O N S >-------------------------------------- each of these counts against the Lua upvalue limit ]] local validation; -- functions in Module:Citation/CS1/Date_validation local utilities; -- functions in Module:Citation/CS1/Utilities local z ={}; -- table of tables in Module:Citation/CS1/Utilities local identifiers;...")
     
    (fixing incorrect import)
     
    Line 1: Line 1:
    <section begin=header />
    require ('Module:No globals');
    {{sandbox other||
    {{#switch:{{FULLPAGENAME}}
    |Module:Citation/CS1={{high-risk |article-space=yes |no-percent=yes}} {{Uses TemplateStyles|Module:Citation/CS1/styles.css}}
    |Module:Citation/CS1/Configuration={{high-risk |article-space=yes |no-percent=yes}}
    |Module:Citation/CS1/Whitelist={{high-risk |article-space=yes |no-percent=yes}}
    |Module:Citation/CS1/Date validation={{high-risk |article-space=yes |no-percent=yes}}
    |Module:Citation/CS1/Identifiers={{high-risk |article-space=yes |no-percent=yes}}
    |Module:Citation/CS1/Utilities={{high-risk |article-space=yes |no-percent=yes}}
    |Module:Citation/CS1/COinS={{high-risk |article-space=yes |no-percent=yes}}
    |Module:Citation/CS1/Suggestions={{high-use |article-space=yes |no-percent=yes}}
    }}
    {{Module rating|p}}}}<!-- if pagename does not contain sandbox -->
    <section end=header />


    This module and associated sub-modules support the {{cs1}} and {{cs2}} citation templates. In general, it is not intended to be called directly, but is called by one of the core CS1 and CS2 templates.
    --[[--------------------------< F O R W A R D D E C L A R A T I O N S >--------------------------------------
    <section begin=module_components_table />
    These files comprise the module support for CS1|2 citation templates:
    {| class="wikitable" style="margin: 1em auto 1em auto;"
    |+CS1 {{pipe}} CS2 modules
    |-
    !colspan="2"|live!!colspan="2"|sandbox!!diff!!description
    |-
    | rowspan="8"| [[File:Full-protection-shackle.svg|20px|alt=Gold padlock|link=|sysop]] || [[Module:Citation/CS1]] || [[Module:Citation/CS1/sandbox]] || {{Plain link|url=https://en.wikipedia.org/w/index.php?title=Module:Citation/CS1/sandbox&action=edit|name=[edit<nowiki>]</nowiki>}} ||[https://en.wikipedia.org/wiki/Special:ComparePages?page1=Module%3ACitation%2FCS1&rev1=&page2=Module%3ACitation%2FCS1%2Fsandbox&rev2=&action=&diffonly=&unhide= diff]|| Rendering and support functions
    |-
    | [[Module:Citation/CS1/Configuration]] || [[Module:Citation/CS1/Configuration/sandbox]] || {{Plain link|url=https://en.wikipedia.org/w/index.php?title=Module:Citation/CS1/Configuration/sandbox&action=edit|name=[edit<nowiki>]</nowiki>}} ||[https://en.wikipedia.org/wiki/Special:ComparePages?page1=Module%3ACitation%2FCS1%2FConfiguration&rev1=&page2=Module%3ACitation%2FCS1%2FConfiguration%2Fsandbox&rev2=&action=&diffonly=&unhide= diff]|| Translation tables; error and identifier handlers
    |-
    | [[Module:Citation/CS1/Whitelist]] || [[Module:Citation/CS1/Whitelist/sandbox]] || {{Plain link|url=https://en.wikipedia.org/w/index.php?title=Module:Citation/CS1/Whitelist/sandbox&action=edit|name=[edit<nowiki>]</nowiki>}} ||[https://en.wikipedia.org/wiki/Special:ComparePages?page1=Module%3ACitation%2FCS1%2FWhitelist&rev1=&page2=Module%3ACitation%2FCS1%2FWhitelist%2Fsandbox&rev2=&action=&diffonly=&unhide= diff]|| List of active and deprecated CS1{{pipe}}2 parameters
    |-
    | [[Module:Citation/CS1/Date validation]] || [[Module:Citation/CS1/Date validation/sandbox]] || {{Plain link|url=https://en.wikipedia.org/w/index.php?title=Module:Citation/CS1/Date_validation/sandbox&action=edit|name=[edit<nowiki>]</nowiki>}} ||[https://en.wikipedia.org/wiki/Special:ComparePages?page1=Module%3ACitation%2FCS1%2FDate+validation&rev1=&page2=Module%3ACitation%2FCS1%2FDate+validation%2Fsandbox&rev2=&action=&diffonly=&unhide= diff] || Date format validation functions
    |-
    | [[Module:Citation/CS1/Identifiers]] || [[Module:Citation/CS1/Identifiers/sandbox]] || {{Plain link|url=https://en.wikipedia.org/w/index.php?title=Module:Citation/CS1/Identifiers/sandbox&action=edit|name=[edit<nowiki>]</nowiki>}} ||[https://en.wikipedia.org/wiki/Special:ComparePages?page1=Module%3ACitation%2FCS1%2FIdentifiers&rev1=&page2=Module%3ACitation%2FCS1%2FIdentifiers%2Fsandbox&rev2=&action=&diffonly=&unhide= diff]|| Functions that support the named identifiers (ISBN, DOI, PMID, etc.)
    |-
    | [[Module:Citation/CS1/Utilities]] || [[Module:Citation/CS1/Utilities/sandbox]] || {{Plain link|url=https://en.wikipedia.org/w/index.php?title=Module:Citation/CS1/Utilities/sandbox&action=edit|name=[edit<nowiki>]</nowiki>}} ||[https://en.wikipedia.org/wiki/Special:ComparePages?page1=Module%3ACitation%2FCS1%2FUtilities&rev1=&page2=Module%3ACitation%2FCS1%2FUtilities%2Fsandbox&rev2=&action=&diffonly=&unhide= diff]|| Common functions and tables
    |-
    | [[Module:Citation/CS1/COinS]] || [[Module:Citation/CS1/COinS/sandbox]] || {{Plain link|url=https://en.wikipedia.org/w/index.php?title=Module:Citation/CS1/COinS/sandbox&action=edit|name=[edit<nowiki>]</nowiki>}} ||[https://en.wikipedia.org/wiki/Special:ComparePages?page1=Module%3ACitation%2FCS1%2FCOinS&rev1=&page2=Module%3ACitation%2FCS1%2FCOinS%2Fsandbox&rev2=&action=&diffonly=&unhide= diff]|| Functions that render a CS1{{pipe}}2 template's metadata
    |-
    | [[Module:Citation/CS1/styles.css]] || [[Module:Citation/CS1/sandbox/styles.css]] || {{Plain link|url=https://en.wikipedia.org/w/index.php?title=Module:Citation/CS1/sandbox/styles.css&action=edit|name=[edit<nowiki>]</nowiki>}} ||[https://en.wikipedia.org/wiki/Special:ComparePages?page1=Module%3ACitation%2FCS1%2Fstyles.css&rev1=&page2=Module%3ACitation%2FCS1%2Fsandbox%2Fstyles.css&rev2=&action=&diffonly=&unhide= diff]|| [[CSS]] styles applied to the CS1{{pipe}}2 templates
    |-
    | [[File:Template-protection-shackle.svg|20px|alt=Silver padlock|link=|auto confirmed]] || [[Module:Citation/CS1/Suggestions]] || [[Module:Citation/CS1/Suggestions/sandbox]] || {{Plain link|url=https://en.wikipedia.org/w/index.php?title=Module:Citation/CS1/Suggestions/sandbox&action=edit|name=[edit<nowiki>]</nowiki>}} ||[https://en.wikipedia.org/wiki/Special:ComparePages?page1=Module%3ACitation%2FCS1%2FSuggestions&rev1=&page2=Module%3ACitation%2FCS1%2FSuggestions%2Fsandbox&rev2=&action=&diffonly=&unhide= diff]|| List that maps common erroneous parameter names to valid parameter names
    |}
    <section end=module_components_table />


    Other documentation:
    each of these counts against the Lua upvalue limit
    * [[Module talk:Citation/CS1/Feature requests]]
    * [[Module talk:Citation/CS1/COinS]]
    * [[Module:Cs1 documentation support]] – a set of functions (some experimental) that extract information from the module suite for the purpose of documenting CS1|2
    ** [[Module:Citation/CS1/doc/Category list]] – lists of category names taken directly from [[Module:Citation/CS1/Configuration]] and [[Module:Citation/CS1/Configuration/sandbox]]
    testcases
    *[[Module:Citation/CS1/testcases]] ([[Module talk:Citation/CS1/testcases|run]])
    *[[Module:Citation/CS1/testcases/errors]] ([[Module talk:Citation/CS1/testcases/errors|run]]) – error and maintenance messaging
    *[[Module:Citation/CS1/testcases/dates]] ([[Module talk:Citation/CS1/testcases/dates|run]]) – date validation
    *[[Module:Citation/CS1/testcases/identifiers]] ([[Module talk:Citation/CS1/testcases/identifiers|run]]) – identifiers
    *[[Module:Citation/CS1/testcases/anchor]] ([[Module talk:Citation/CS1/testcases/anchor|run]]) – CITEREF anchors


    <includeonly>{{sandbox other||
    ]]
    [[Category:Modules that add a tracking category]]

    {{#ifeq:{{SUBPAGENAME}}|Identifiers|[[Category:Modules using data from Wikidata]]}}
    local validation; -- functions in Module:Citation/CS1/Date_validation
    }}</includeonly>

    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 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 ({'cash', 'company', 'today', 'org'}) do -- look for single letter second level domain names for these top level domains
    if domain:match ('%f[%w][%w]%.' .. d) then
    return true
    end
    end
    return false; -- no matches, we don't know what this thing is
    end


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

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

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

    ]]

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


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

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

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

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

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

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

    Strip off any port and path;

    ]]

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

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


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

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

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

    returns false when the value contains any of these characters.

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

    ]]

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

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


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

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

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

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

    ]]

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

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

    if utilities.is_set (orig) then
    link = ''; -- unset
    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"]);
    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_code_remap[lang] or mw.language.fetchLanguageName( lang, cfg.this_wiki_code ); -- get language name so that we can use it to categorize
    if utilities.is_set (name) then -- is prefix a proper ISO 639-1 language code?
    script_value = script_value:gsub ('^%l+%s*:%s*', ''); -- strip prefix from script
    -- is prefix one of these language codes?
    if utilities.in_array (lang, cfg.script_lang_codes) then
    utilities.add_prop_cat ('script', {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[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]+(.+)$'); -- get generational suffix
    end
    end
    if utilities.is_set (suffix) then
    if not is_suffix (suffix) then
    add_vanc_error (cfg.err_msg_supl.suffix, position);
    return false; -- not a name with an appropriate suffix
    end
    end
    if nil == mw.ustring.find (last, "^[A-Za-z\195\128-\195\150\195\152-\195\182\195\184-\198\191\199\132-\201\143%-%s%']*$") or
    nil == mw.ustring.find (first, "^[A-Za-z\195\128-\195\150\195\152-\195\182\195\184-\198\191\199\132-\201\143%-%s%'%.]*$") then
    add_vanc_error (cfg.err_msg_supl['non-Latin char'], position);
    return false; -- not a string of Latin characters; Vancouver requires Romanization
    end;
    return true;
    end


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

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

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

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

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

    ]]

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

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

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

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

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

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


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

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

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

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

    ]]

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

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

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

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

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


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

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

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

    ]]

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


    --[[--------------------------< 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 maint cat when name parameter value does not contain letters. Does not catch
    mixed alphanumeric names so |last=A. Green (1922-1987) does not get caught in the
    current version of this test but |first=(1888) is caught.

    returns nothing

    ]]

    local function name_is_numeric (name, list_name)
    if utilities.is_set (name) then
    if mw.ustring.match (name, '^[%A]+$') then -- when name does not contain any letters
    utilities.set_message ('maint_numeric_names', cfg.special_case_translation [list_name]); -- add a maint cat for this template
    end
    end
    end


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

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

    returns nothing

    ]]

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


    --[=[-------------------------< 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 (last only)
    name_is_numeric (last, list_name); -- check for names that are composed of digits and punctuation
    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_is_numeric (first, list_name); -- check for names that are composed of digits and punctuation
    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 );

    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_code_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_code_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
    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_code_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 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

    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

    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 = 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, lang_subtag}, lang_subtag); -- categorize it; tag appended to allow for multiple language categorization
    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 'citation' == cite_class then
    utilities.set_message ('maint_postscript');
    end
    postscript = '';
    end
    return sep, postscript
    end


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

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

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

    ]=]

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


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

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

    ]]

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


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

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

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

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

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

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

    ]]

    local function get_display_names (max, count, list_name, etal, param)
    if utilities.is_set (max) then
    if 'etal' == max:lower():gsub("[ '%.]", '') then -- the :gsub() portion makes 'etal' from a variety of 'et al.' spellings and stylings
    max = count + 1; -- number of authors + 1 so display all author name plus et al.
    etal = true; -- overrides value set by extract_names()
    elseif max:match ('^%d+$') then -- if is a string of numbers
    max = tonumber (max); -- make it a number
    if max >= count then -- if |display-xxxxors= value greater than or equal to number of authors/editors
    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.

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

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

    sets error message on failure; returns nothing

    ]]

    local function extra_text_in_vol_iss_check (val, name, selector)
    if not utilities.is_set (val) then
    return;
    end
    local patterns = 'v' == selector and cfg.vol_iss_pg_patterns.vpatterns or cfg.vol_iss_pg_patterns.ipatterns;

    local handler = 'v' == selector and 'err_extra_text_volume' or 'err_extra_text_issue';
    val = val:lower(); -- force parameter value to lower case
    for _, pattern in ipairs (patterns) do -- spin through the selected sequence table of patterns
    if val:match (pattern) then -- when a match, error so
    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 parameters as a single string; or formatted volume
    or formatted issue, or an empty string if neither are set.

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

    -- 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
    if utilities.is_set (issue) then
    return vol .. utilities.substitute (cfg.messages['j-issue'], issue);
    end
    return vol;
    end
    if 'podcast' == cite_class and utilities.is_set (issue) then
    return wrap_msg ('issue', {sepc, issue}, lower);
    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*/)

    ]=]

    local function archive_url_check (url, date)
    local err_msg = ''; -- start with the error message empty
    local path, timestamp, flag; -- portions of the archive.org URL
    if (not url:match('//web%.archive%.org/')) and (not url:match('//liveweb%.archive%.org/')) then -- also deprecated liveweb Wayback machine URL
    return url, date; -- not an archive.org archive, return ArchiveURL and ArchiveDate
    end

    if url:match('//web%.archive%.org/save/') then -- if a save command URL, we don't want to allow saving of the target page
    err_msg = cfg.err_msg_supl.save;
    url = url:gsub ('(//web%.archive%.org)/save/', '%1/*/', 1); -- for preview mode: modify ArchiveURL
    elseif url:match('//liveweb%.archive%.org/') then
    err_msg = cfg.err_msg_supl.liveweb;
    else
    path, timestamp, flag = url:match('//web%.archive%.org/([^%d]*)(%d+)([^/]*)/'); -- split out some of the URL parts for evaluation
    if not 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; -- return ArchiveURL and ArchiveDate
    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; -- preview mode so return ArchiveURL and ArchiveDate
    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


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

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

    ]]

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

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

    local author_etal;
    local a = {}; -- authors list from |lastn= / |firstn= pairs or |vauthors=
    local Authors;
    local NameListStyle = is_valid_parameter_value (A['NameListStyle'], A:ORIGIN('NameListStyle'), cfg.keywords_lists['name-list-style'], '');
    local Collaboration = A['Collaboration'];

    do -- to limit scope of selected
    local selected = select_author_editor_source (A['Vauthors'], A['Authors'], args, 'AuthorList');
    if 1 == selected then
    a, author_etal = extract_names (args, 'AuthorList'); -- fetch author list from |authorn= / |lastn= / |firstn=, |author-linkn=, and |author-maskn=
    elseif 2 == selected then
    NameListStyle = 'vanc'; -- override whatever |name-list-style= might be
    a, author_etal = parse_vauthors_veditors (args, args.vauthors, 'AuthorList'); -- fetch author list from |vauthors=, |author-linkn=, and |author-maskn=
    elseif 3 == selected then
    Authors = A['Authors']; -- use content of |authors=
    if 'authors' == A:ORIGIN('Authors') then -- but add a maint cat if the parameter is |authors=
    utilities.set_message ('maint_authors'); -- because use of this parameter is discouraged; what to do about the aliases is a TODO:
    end
    end
    if utilities.is_set (Collaboration) then
    author_etal = true; -- so that |display-authors=etal not required
    end
    end

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

    do -- to limit scope of selected
    local selected = select_author_editor_source (A['Veditors'], nil, args, 'EditorList'); -- support for |editors= withdrawn
    if 1 == selected then
    e, editor_etal = extract_names (args, 'EditorList'); -- fetch editor list from |editorn= / |editor-lastn= / |editor-firstn=, |editor-linkn=, and |editor-maskn=
    elseif 2 == selected then
    NameListStyle = 'vanc'; -- override whatever |name-list-style= might be
    e, editor_etal = parse_vauthors_veditors (args, args.veditors, 'EditorList'); -- fetch editor list from |veditors=, |editor-linkn=, and |editor-maskn=
    end
    end
    local Chapter = A['Chapter']; -- done here so that we have access to |contribution= from |chapter= aliases
    local Chapter_origin = A:ORIGIN ('Chapter');
    local Contribution; -- because contribution is required for contributor(s)
    if 'contribution' == Chapter_origin then
    Contribution = Chapter; -- get the name of the contribution
    end
    local c = {}; -- contributors list from |contributor-lastn= / contributor-firstn= pairs
    if utilities.in_array (config.CitationClass, {"book", "citation"}) and not utilities.is_set (A['Periodical']) then -- |contributor= and |contribution= only supported in book cites
    c = extract_names (args, 'ContributorList'); -- fetch contributor list from |contributorn= / |contributor-lastn=, -firstn=, -linkn=, -maskn=
    if 0 < #c then
    if not utilities.is_set (Contribution) then -- |contributor= requires |contribution=
    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 = '';
    if utilities.is_set (Periodical) then
    Periodical_origin = A:ORIGIN('Periodical'); -- get the name of the periodical parameter
    local i;
    Periodical, i = utilities.strip_apostrophe_markup (Periodical); -- strip apostrophe markup so that metadata isn't contaminated
    if i then -- non-zero when markup was stripped so emit an error message
    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) .. ' and ' .. 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

    local ScriptPeriodical = A['ScriptPeriodical'];

    -- web and news not tested for now because of
    -- Wikipedia:Administrators%27_noticeboard#Is_there_a_semi-automated_tool_that_could_fix_these_annoying_"Cite_Web"_errors?
    if not (utilities.is_set (Periodical) or utilities.is_set (ScriptPeriodical)) then -- 'periodical' templates require periodical parameter
    -- local p = {['journal'] = 'journal', ['magazine'] = 'magazine', ['news'] = 'newspaper', ['web'] = 'website'}; -- for error message
    local p = {['journal'] = 'journal', ['magazine'] = 'magazine'}; -- for error message
    if p[config.CitationClass] then
    utilities.set_message ('err_missing_periodical', {config.CitationClass, p[config.CitationClass]});
    end
    end
    local Volume;
    local ScriptPeriodical_origin = A:ORIGIN('ScriptPeriodical');
    if 'citation' == config.CitationClass then
    if utilities.is_set (Periodical) then
    if not utilities.in_array (Periodical_origin, 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
    extra_text_in_vol_iss_check (Issue, A:ORIGIN ('Issue'), 'i');

    local Page;
    local Pages;
    local At;
    if not utilities.in_array (config.CitationClass, cfg.templates_not_using_page) then
    Page = A['Page'];
    Pages = utilities.hyphen_to_dash (A['Pages']);
    At = A['At'];
    end

    local Edition = A['Edition'];
    local PublicationPlace = place_check (A['PublicationPlace'], A:ORIGIN('PublicationPlace'));
    local Place = place_check (A['Place'], A:ORIGIN('Place'));
    local PublisherName = A['PublisherName'];
    local PublisherName_origin = A:ORIGIN('PublisherName');
    if utilities.is_set (PublisherName) then
    local i = 0;
    PublisherName, i = utilities.strip_apostrophe_markup (PublisherName); -- strip apostrophe markup so that metadata isn't contaminated; publisher is never italicized
    if i then -- non-zero when markup was stripped so emit an error message
    utilities.set_message ('err_apostrophe_markup', {PublisherName_origin});
    end
    end

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

    if 'newsgroup' == config.CitationClass then
    if utilities.is_set (PublisherName) then -- general use parameter |publisher= not allowed in cite newsgroup
    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 utilities.in_array (this_page.nsText, cfg.uncategorized_namespaces) then
    no_tracking_cats = "true"; -- set no_tracking_cats
    end
    for _, v in ipairs (cfg.uncategorized_subpages) do -- cycle through page name patterns
    if this_page.text:match (v) then -- test page name against each pattern
    no_tracking_cats = "true"; -- set no_tracking_cats
    break; -- bail out if one is found
    end
    end
    end
    -- check for extra |page=, |pages= or |at= parameters. (also sheet and sheets while we're at it)
    utilities.select_one (args, {'page', 'p', 'pp', 'pages', 'at', 'sheet', 'sheets'}, 'err_redundant_parameters'); -- this is a dummy call simply to get the error message and category

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

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

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

    if PublicationPlace == Place then Place = ''; end -- don't need both if they are the same
    local URL_origin = A:ORIGIN('URL'); -- get name of parameter that holds URL
    local ChapterURL_origin = A:ORIGIN('ChapterURL'); -- get name of parameter that holds ChapterURL
    local ScriptChapter = A['ScriptChapter'];
    local ScriptChapter_origin = A:ORIGIN ('ScriptChapter');
    local Format = A['Format'];
    local ChapterFormat = A['ChapterFormat'];
    local TransChapter = A['TransChapter'];
    local TransChapter_origin = A:ORIGIN ('TransChapter');
    local TransTitle = A['TransTitle'];
    local ScriptTitle = A['ScriptTitle'];
    --[[
    Parameter remapping for cite encyclopedia:
    When the citation has these parameters:
    |encyclopedia= and |title= then map |title= to |article= and |encyclopedia= to |title=
    |encyclopedia= and |article= then map |encyclopedia= to |title=

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

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

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

    if ('encyclopaedia' == config.CitationClass) or ('citation' == config.CitationClass and utilities.is_set (Encyclopedia)) then
    if utilities.is_set (Periodical) and utilities.is_set (Encyclopedia) then -- when both set emit an error TODO: make a function for this and similar?
    utilities.set_message ('err_redundant_parameters', {utilities.wrap_style ('parameter', A:ORIGIN ('Encyclopedia')) .. ' and ' .. utilities.wrap_style ('parameter', Periodical_origin)});
    end

    if utilities.is_set (Encyclopedia) then
    Periodical = Encyclopedia; -- error or no, set Periodical to Encyclopedia; allow periodical without encyclopedia
    Periodical_origin = A:ORIGIN ('Encyclopedia');
    end

    if utilities.is_set (Periodical) then -- Periodical is set when |encyclopedia= is set
    if utilities.is_set (Title) or utilities.is_set (ScriptTitle) then
    if not utilities.is_set (Chapter) then
    Chapter = Title; -- |encyclopedia= and |title= are set so map |title= to |article= and |encyclopedia= to |title=
    ScriptChapter = ScriptTitle;
    ScriptChapter_origin = A:ORIGIN('ScriptTitle')
    TransChapter = TransTitle;
    ChapterURL = URL;
    ChapterURL_origin = URL_origin;

    ChapterUrlAccess = UrlAccess;

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

    -- special case for cite techreport.
    local ID = A['ID'];
    if (config.CitationClass == "techreport") then -- special case for cite techreport
    if utilities.is_set (A['Number']) then -- cite techreport uses 'number', which other citations alias to 'issue'
    if not utilities.is_set (ID) then -- can we use ID for the "number"?
    ID = A['Number']; -- yes, use it
    else -- ID has a value so emit error message
    utilities.set_message ('err_redundant_parameters', {utilities.wrap_style ('parameter', 'id') .. ' and ' .. 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 = is_valid_parameter_value (A['Mode'], A:ORIGIN('Mode'), cfg.keywords_lists['mode'], '');
    -- separator character and postscript
    local sepc, PostScript = set_style (Mode:lower(), A['PostScript'], config.CitationClass);
    -- controls capitalization of certain static text
    local use_lowercase = ( sepc == ',' );
    -- cite map oddities
    local Cartography = "";
    local Scale = "";
    local Sheet = A['Sheet'] or '';
    local Sheets = A['Sheets'] or '';
    if config.CitationClass == "map" then
    if utilities.is_set (Chapter) then --TODO: make a function for this and similar?
    utilities.set_message ('err_redundant_parameters', {utilities.wrap_style ('parameter', 'map') .. ' and ' .. 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') .. ' and ' .. 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', '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'];

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

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

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

    -- start temporary Julian / Gregorian calendar uncertainty categorization
    if COinS_date.inter_cal_cat then
    utilities.add_prop_cat ('jul-greg-uncertainty');
    end
    -- end temporary Julian / Gregorian calendar uncertainty categorization

    if utilities.is_set (Year) and utilities.is_set (Date) then -- both |date= and |year= not normally needed;
    validation.year_date_check (Year, A:ORIGIN ('Year'), Date, A:ORIGIN ('Date'), error_list);
    end
    if 0 == #error_list then -- error free dates only; 0 when error_list is empty
    local modified = false; -- flag
    if 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;
    LayDate = date_parameters_list['lay-date'].val;
    PublicationDate = date_parameters_list['publication-date'].val;
    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

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

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

    -- Account for the oddities that are {{cite arxiv}}, {{cite biorxiv}}, {{cite citeseerx}}, {{cite ssrn}}, before generation of COinS data.
    if utilities.in_array (config.CitationClass, whitelist.preprint_template_list) then
    if not utilities.is_set (ID_list_coins[config.CitationClass:upper()]) then -- |arxiv= or |eprint= required for cite arxiv; |biorxiv= & |citeseerx= required for their templates
    utilities.set_message ('err_' .. config.CitationClass .. '_missing'); -- add error message
    end

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

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

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

    if utilities.is_set (URL) 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
    local QuotePage = A['QuotePage'];
    local QuotePages = utilities.hyphen_to_dash (A['QuotePages']);

    -- this is the function call to COinS()
    local OCinSoutput = metadata.COinS({
    ['Periodical'] = utilities.strip_apostrophe_markup (Periodical), -- no markup in the metadata
    ['Encyclopedia'] = Encyclopedia, -- just a flag; content ignored by ~/COinS
    ['Chapter'] = metadata.make_coins_title (coins_chapter, ScriptChapter), -- Chapter and ScriptChapter stripped of bold / italic / 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 if Date is valid;
    ['Season'] = COinS_date.rftssn,
    ['Quarter'] = COinS_date.rftquarter,
    ['Chron'] = COinS_date.rftchron or (not COinS_date.rftdate and Date) or '', -- chron but if not set and invalid date format use Date; keep this last bit?
    ['Series'] = Series,
    ['Volume'] = Volume,
    ['Issue'] = Issue,
    ['Pages'] = coins_pages or metadata.get_coins_pages (first_set ({Sheet, Sheets, Page, Pages, At, QuotePage, QuotePages}, 7)), -- pages stripped of external links
    ['Edition'] = Edition,
    ['PublisherName'] = PublisherName or Newsgroup, -- any apostrophe markup already removed from PublisherName
    ['URL'] = first_set ({ChapterURL, URL}, 2),
    ['Authors'] = coins_author,
    ['ID_list'] = ID_list_coins,
    ['RawPage'] = this_page.prefixedText,
    }, config.CitationClass);

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

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

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

    do -- do editor name list first because the now unsupported coauthors used to modify control table
    control.maximum , editor_etal = get_display_names (A['DisplayEditors'], #e, 'editors', editor_etal, A:ORIGIN ('DisplayEditors'));
    Editors, EditorCount = list_people (control, e, editor_etal);

    if 1 == EditorCount and (true == editor_etal or 1 < #e) then -- only one editor displayed but includes etal then
    EditorCount = 2; -- spoof to display (eds.) annotation
    end
    end
    do -- now do interviewers
    control.maximum, interviewer_etal = get_display_names (A['DisplayInterviewers'], #interviewers_list, 'interviewers', interviewer_etal, A:ORIGIN ('DisplayInterviewers'));
    Interviewers = list_people (control, interviewers_list, interviewer_etal);
    end
    do -- now do translators
    control.maximum, translator_etal = get_display_names (A['DisplayTranslators'], #t, 'translators', translator_etal, A:ORIGIN ('DisplayTranslators'));
    Translators = list_people (control, t, translator_etal);
    end
    do -- now do contributors
    control.maximum, contributor_etal = get_display_names (A['DisplayContributors'], #c, 'contributors', contributor_etal, A:ORIGIN ('DisplayContributors'));
    Contributors = list_people (control, c, contributor_etal);
    end
    do -- now do authors
    control.maximum, author_etal = get_display_names (A['DisplayAuthors'], #a, 'authors', author_etal, A:ORIGIN ('DisplayAuthors'));

    last_first_list = list_people (control, a, author_etal);

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

    end

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

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

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

    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') .. ' and ' .. 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'];
    Agency = utilities.is_set (Agency) and wrap_msg ('agency', {sepc, Agency}) or "";
    Volume = format_volume_issue (Volume, Issue, config.CitationClass, Periodical_origin, sepc, use_lowercase);

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

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

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

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

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

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

    Quote = utilities.wrap_style ('quoted-text', Quote ); -- wrap in <q>...</q> tags
    if utilities.is_set (ScriptQuote) then
    Quote = script_concatenate (Quote, ScriptQuote, 'script-quote'); -- <bdi> tags, lang attribute, categorization, etc.; must be done after quote is wrapped
    end

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

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

    PostScript = ""; -- cs1|2 does not supply terminal punctuation when |quote= is set
    end
    -- We check length of PostScript here because it will have been nuked by
    -- the quote parameters. We'd otherwise emit a message even if there wasn't
    -- a displayed postscript.
    -- TODO: Should the max size (1) be configurable?
    -- TODO: Should we check a specific pattern?
    if utilities.is_set(PostScript) and mw.ustring.len(PostScript) > 1 then
    utilities.set_message ('maint_postscript')
    end
    local Archived;
    if utilities.is_set (ArchiveURL) then
    local arch_text;
    if not utilities.is_set (ArchiveDate) then
    utilities.set_message ('err_archive_missing_date');
    ArchiveDate = ''; -- empty string for concatenation
    end
    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
    arch_text = cfg.messages['archived-missing'];
    if sepc ~= "." then arch_text = arch_text:lower() end
    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 Lay = '';
    local LaySource = A['LaySource'];
    local LayURL = A['LayURL'];
    local LayFormat = A['LayFormat'];
    LayFormat = style_format (LayFormat, LayURL, 'lay-format', 'lay-url');
    if utilities.is_set (LayURL) then
    if utilities.is_set (LayDate) then LayDate = " (" .. LayDate .. ")" end
    if utilities.is_set (LaySource) then
    LaySource = " &ndash; ''" .. utilities.safe_for_italics (LaySource) .. "''";
    else
    LaySource = "";
    end
    if sepc == '.' then
    Lay = sepc .. " " .. external_link( LayURL, cfg.messages['lay summary'], A:ORIGIN('LayURL'), nil ) .. LayFormat .. LaySource .. LayDate
    else
    Lay = sepc .. " " .. external_link( LayURL, cfg.messages['lay summary']:lower(), A:ORIGIN('LayURL'), nil ) .. LayFormat .. LaySource .. LayDate
    end
    elseif utilities.is_set (LayFormat) then -- Test if |lay-format= is given without giving a |lay-url=
    Lay = sepc .. LayFormat; -- if set and LayURL not set, then LayFormat has error message
    end

    local TranscriptURL = A['TranscriptURL']
    local TranscriptFormat = A['TranscriptFormat'];
    TranscriptFormat = style_format (TranscriptFormat, TranscriptURL, 'transcript-format', 'transcripturl');
    local Transcript = A['Transcript'];
    local TranscriptURL_origin = A:ORIGIN('TranscriptURL'); -- get name of parameter that holds TranscriptURL
    if utilities.is_set (Transcript) then
    if utilities.is_set (TranscriptURL) then
    Transcript = external_link( TranscriptURL, Transcript, TranscriptURL_origin, nil );
    end
    Transcript = sepc .. ' ' .. Transcript .. TranscriptFormat;
    elseif utilities.is_set (TranscriptURL) then
    Transcript = external_link( TranscriptURL, nil, TranscriptURL_origin, nil );
    end

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

    --[[
    Handle the oddity that is cite speech. This code overrides whatever may be the value assigned to TitleNote (through |department=) and forces it to be " (Speech)" so that
    the annotation directly follows the |title= parameter value in the citation rather than the |event= parameter value (if provided).
    ]]
    if "speech" == config.CitationClass then -- cite speech only
    TitleNote = 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, {"journal", "citation"}) and utilities.is_set (Periodical) then
    if utilities.is_set (Others) then Others = safe_join ({Others, sepc .. " "}, sepc) end -- add terminal punctuation & space; check for dup sepc; TODO why do we need to do this here?
    tcommon = safe_join( {Others, Title, TitleNote, Conference, Periodical, Format, TitleType, Series, Language, Edition, Publisher, Agency, Volume}, sepc );
    elseif utilities.in_array (config.CitationClass, {"book", "citation"}) and not utilities.is_set (Periodical) then -- special cases for book cites
    if utilities.is_set (Contributors) then -- when we are citing foreword, preface, introduction, etc.
    tcommon = safe_join( {Title, TitleNote}, sepc ); -- author and other stuff will come after this and before tcommon2
    tcommon2 = safe_join( {Conference, Periodical, Format, TitleType, Series, Language, Volume, Others, Edition, Publisher, Agency}, sepc );
    else
    tcommon = safe_join( {Title, TitleNote, Conference, Periodical, Format, TitleType, Series, Language, Volume, Others, Edition, Publisher, Agency}, sepc );
    end

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

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

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

    -- Now enclose the whole thing in a <cite> element
    local options_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
    for _, v in ipairs (z.error_cats_t) do -- append error categories
    table.insert (render_t, utilities.substitute (cfg.messages['cat wikilink'], v));
    end
    for _, v in ipairs (z.maint_cats_t) do -- append maintenance categories
    table.insert (render_t, utilities.substitute (cfg.messages['cat wikilink'], v));
    end
    for _, v in ipairs (z.prop_cats_t) do -- append properties categories
    table.insert (render_t, utilities.substitute (cfg.messages['cat wikilink'], v));
    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; -- for enumerated parameters, is name with enumerator replaced with '#'
    local state;
    local function state_test (state, name) -- local function to do testing of state values
    if true == state then return true; end -- valid actively supported parameter
    if false == state then
    if empty then return nil; end -- empty deprecated parameters are treated as unknowns
    deprecated_parameter (name); -- parameter is deprecated but still supported
    return true;
    end
    if '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

    if utilities.in_array (cite_class, whitelist.preprint_template_list ) then -- limited parameter sets allowed for these templates
    state = whitelist.limited_basic_arguments[name];
    if true == state_test (state, name) then return true; end

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

    -- limited enumerated parameters list
    enum_name = name:gsub("%d+", "#" ); -- replace digit(s) with # (last25 becomes last#) (mw.ustring because non-Western 'local' digits)
    state = whitelist.limited_numbered_arguments[enum_name];
    if true == state_test (state, name) then return true; end

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

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

    -- all enumerated parameters allowed
    enum_name = name:gsub("%d+", "#" ); -- replace digit(s) with # (last25 becomes last#) (mw.ustring because non-Western 'local' digits)
    state = whitelist.numbered_arguments[enum_name];
    if true == state_test (state, name) then return true; end

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


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

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

    return value as is else

    ]=]

    local function inter_wiki_check (parameter, value)
    local prefix = value:match ('%[%[(%a+):'); -- get an interwiki prefix if one exists
    local _;
    if prefix and cfg.inter_wiki_map[prefix:lower()] then -- if prefix is in the map, needs preceding colon so
    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 sandbox = '/sandbox' -- i18n: replace this rvalue with the name that your wiki uses to identify sandbox subpages
    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 config = {}; -- table to store parameters from the module {{#invoke:}}
    for k, v in pairs( frame.args ) do -- get parameters from the {{#invoke}} frame
    config[k] = v;
    -- args[k] = v; -- crude debug support that allows us to render a citation from module {{#invoke:}}; skips parameter validation; TODO: keep?
    end

    local capture; -- the single supported capture when matching unknown parameters using patterns
    local empty_unknowns = {}; -- sequence table to hold empty unknown params for error message listing
    for k, v in pairs( pframe.args ) do -- get parameters from the parent (template) frame
    v = mw.ustring.gsub (v, '^%s*(.-)%s*$', '%1'); -- trim leading/trailing whitespace; when v is only whitespace, becomes empty string
    if v ~= '' then
    if ('string' == type (k)) then
    k = mw.ustring.gsub (k, '%d', cfg.date_names.local_digits); -- for enumerated parameters, translate 'local' digits to Western 0-9
    end
    if not validate( k, config.CitationClass ) then
    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
    if is_sandbox then -- did the {{#invoke:}} use sandbox version?
    suggestions = mw.loadData( 'Module:Citation/CS1/Suggestions/sandbox' ); -- use the sandbox version
    else
    suggestions = mw.loadData( 'Module:Citation/CS1/Suggestions' ); -- use the live version
    end
    end
    for pattern, param in pairs (suggestions.patterns) do -- loop through the patterns to see if we can suggest a proper parameter
    capture = k:match (pattern); -- the whole match if no capture in pattern else the capture if a match
    if capture then -- if the pattern matches
    param = utilities.substitute (param, capture); -- add the capture to the suggested parameter (typically the enumerator)
    if validate (param, config.CitationClass) then -- validate the suggestion to make sure that the suggestion is supported by this template (necessary for limited parameter lists)
    error_text = 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};

    Latest revision as of 18:17, 24 October 2022

    This module and associated sub-modules support the Template:Cs1 and Template:Cs2 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 diff Rendering and support functions
    Module:Citation/CS1/Configuration Module:Citation/CS1/Configuration/sandbox diff Translation tables; error and identifier handlers
    Module:Citation/CS1/Whitelist Module:Citation/CS1/Whitelist/sandbox diff List of active and deprecated CS12 parameters
    Module:Citation/CS1/Date validation Module:Citation/CS1/Date validation/sandbox diff Date format validation functions
    Module:Citation/CS1/Identifiers Module:Citation/CS1/Identifiers/sandbox diff Functions that support the named identifiers (ISBN, DOI, PMID, etc.)
    Module:Citation/CS1/Utilities Module:Citation/CS1/Utilities/sandbox diff Common functions and tables
    Module:Citation/CS1/COinS Module:Citation/CS1/COinS/sandbox diff Functions that render a CS12 template's metadata
    Module:Citation/CS1/styles.css Module:Citation/CS1/sandbox/styles.css diff CSS styles applied to the CS12 templates
    Silver padlock Module:Citation/CS1/Suggestions Module:Citation/CS1/Suggestions/sandbox diff List that maps common erroneous parameter names to valid parameter names

    Other documentation:

    testcases


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