Help:Citation Style 1

Citation Style 1 (CS1) is a collection of reference citation templates that can be modified to create different styles for different referenced materials. Its purpose is to provide a set of default formats for references on Wikipedia. It includes a series of templates that in turn use Module:Citation/CS1.

The use of CS1 or of templates is not compulsory; per WP:CITEVAR:

"Wikipedia does not have a single house style. Editors may choose any option they want; one article need not match what is done in other articles or what is done in professional publications or recommended by academic style guides. However, citations within a given article should follow a consistent style."

CS1 uses elements of The Chicago Manual of Style and the Publication Manual of the American Psychological Association, with significant adaptations.

Style
There are a number of templates that use a name starting with cite; many were developed independently of CS1 and are not compliant with the CS1 style. There are also a number of templates that use one of the general use templates as a meta-template to cite a specific source.

To be compliant with CS1, a template must:
 * Use Module:Citation/CS1 or one of the templates listed below.
 * Use a period as a punctuation mark to separate fields and end the citation.
 * Use a semicolon as a punctuation mark to separate authors and editors.
 * Format the title of longer works in italics.
 * Format the title of short works such as chapters in quotes.

General use
The following is a list of templates that implement Citation Style 1 for one or more types of citations but are not restricted to any specific source.

Specific source
There are a number of templates that are CS1 compliant, because they use a CS1 template as a base, but are tied to a specific source; these are listed in Category:Citation Style 1 specific-source templates.

How the templates work
CS1 uses a series of templates that provide a consistent output. The main difference is in parameters optimized for the subject. For example, cite book has fields for title and chapter, whereas cite journal has fields for journal and title.

This help page uses the names most commonly used across the templates series; see each template's documentation for details.

CS1 templates present a citation generally as:
 * With author:


 * Without author:

(where "n.d." could also be any other valid date formatted per the MOS)

Authors
An author may be cited using separate parameters for the author's surname and given name by using last and first respectively. If a cited source has multiple authors, subsequent authors can be listed in the citation using last2 and first2, last3 and first3, etc. as shown in the following example:





If a cited source has a large number of authors, one can limit the number of authors displayed when the citation is published by using the display-authors parameter as described in detail in the Display options section of this help page.

If a cited author is notable and the author has a Wikipedia article, the author's name can be linked with author-link. If a citation includes multiple notable authors, one may use author-link2, author-link3, etc. This method is used because last and first do not allow wikilinking. Please note that author-link cannot be used to link to an external website; the external link will not render correctly. Below is an example of a wikilinked author credit:





When an author is cited, the date of the cited work is displayed after the author's name, as shown in the example below:





If no author is cited, the date appears after the title, as shown in the example below:





If the cited source does not credit an author, as is common with newswire reports, press releases or company websites use:


 * author

This HTML comment alerts fact-checking and citation-fixing editors, and potentially bots, that the cited source did not name an author—the author was not overlooked. Without this entry editors and bots would waste time researching cited sources for a non-existent author credit.

When using author avoid citations like, unless the article is on a field in which the majority of professional journals covering that field use such a citation style.

Editors should use an author organizational citation when the cited source, such as a committee report, specifically names an official body or a sub-unit of the publisher as the collective author of the work, e.g. Commission on Headphone Safety or Rules Sub-committee. Do not use author to assert what you think was probably the collective author when the source itself does not specifically specify a collective author; doing so is original research and falsification of source verifiability and reliability.

author should never hold the name of more than one author. Separate individual authors into enumerated individual authorn parameters.

Editors
An editor may be cited using separate parameters for the editor's last and first name. A single or first editor would use editor-last and editor-first; subsequent editors would use editor2-last and editor2-first, editor3-last and editor3-first, etc.

If an editor is notable and has a Wikipedia article, you may wikilink to that editor's Wikipedia article using editor-link. If a cited work has multiple editors, you may use editor2-link, editor3-link, etc. to wikilink to each editor's Wikipedia article. This method is used because editor-last and editor-first do not allow wikilinking. Please note that editor-link cannot be used to link to an external website; the external link will not render correctly.

If a cited source has a large number of editors, one can limit the number of editors displayed when the citation is published using the display-editors parameter as described in detail in the Display options section of this help page.

Others

 * others: This parameter is used to credit contributors other than an author or an editor, such as an illustrator or a translator. You should include both the type of contribution and the name of the contributor, for example Illustrated by John Smith or Trans. Jones

Dates
Dates are indicated by these parameters:
 * date: Full date of publication edition being referenced, in the same format as other dates in citations in the same article. Must not be wikilinked.
 * OR: year: Year of publication edition being referenced.
 * orig-year: Original publication year, for display alongside the date or year. For clarity, please supply specifics, for instance  or  . This parameter displays only if there is a value for year or date.

For no date, or "undated", add as

Acceptable date formats are shown in the "Acceptable date formats" table of the Manual of Style/Dates and numbers § Dates, months and years. Further points:
 * Prescriptions about date formats only apply when the date is expressed in terms of Julian or Gregorian dates, or which use one of the seasons (spring, summer, autumn or fall, winter). Sources are at liberty to use other ways of expressing dates, such as "spring-summer" or a date in a religious calendar; editors should report the date as expressed by the source. Although the seasons are not normally capitalized, they are capitalized when used as dates in CS1 templates, and the capitalization of the season stated by the source may be altered to follow this rule.
 * Do not wikilink.
 * Access and archive dates in references should be in either the format used for publication dates, or YYYY-MM-DD.

CS1 compliance with Wikipedia's Manual of Style
CS1 uses Manual of Style/Dates and numbers § Dates, months and years (MOS:DATEFORMAT) as the reference for all date format checking performed by Module:Citation/CS1. For various reasons, CS1 is not fully compliant with MOS:DATEFORMAT. This table indicates CS1 compliance with the listed sections of MOS:DATEFORMAT.

Date range, multiple sources in same year
If dates are used with the ref=harv parameter, the year range is 100 to present without era indication (AD, BC, CE, BCE). In the case where the same author has written more than one work in the same year, a lower-case letter may be appended to the year in the date parameter (date &#61; July 4, 1997b) or the year parameter (year &#61; 1997b).

Titles and chapters

 * title The title of the cited source. Titles are displayed in italics, except for short works such as a cite press release and cited articles in, , , , and , where the title is shown in quotation marks. Use title case unless the cited source covers a scientific, legal or other technical topic and sentence case is the predominant style in journals on that topic. Use either title case or sentence case consistently throughout the article. Do not omit a leading "The" from the title. Subtitles are typically separated from titles with ": " though " – " is also used. As with trademarks, Wikipedia attempt to emulate any stylistic flourishes used by the cited source's publisher, such as ALL-CAPS, all-lower-case, , etc.; use either standard title case or sentence case consistently. If the cited source is itself notable and has a Wikipedia article, the title can be wikilinked. Wikilinking the title will make it impossible to use the "url" parameter to link to an external copy of the cited source, so only do this when citing works that do not need to be externally linked. A link to the actual source is preferred to a link to a Wikipedia article about the source.
 * script-title: Languages that do not use a Latin-based alphabet, Arabic, Chinese, Cyrillic, Greek, Hebrew, Japanese, Korean, etc., should not be italicized and may also read right-to-left (rtl). To include titles in these languages, use script-title. Titles in script-title are wrapped in special HTML markup to isolate rtl script from adjacent left-to-right text.  Part of that special markup is a language attribute that browsers can use to assist in the proper display of the script.  Editors may add a prefix to the script that will identify the language.  The prefix is an ISO 639-1 two-character language code followed by a colon: ar: العربية.  Unrecognized codes are ignored and will display in the rendered citation.
 * trans-title: If the cited source is in a foreign language, an English translation of the title can be given here. This field will be displayed in square brackets after the title and will be linked to url if used.
 * chapter The title of the cited chapter from the source, written in full. Displayed in quotes before the title. For websites arranged in sections the "at" parameter serves a similar function: Featured News
 * script-chapter: Languages that do not use a Latin-based alphabet, Arabic, Chinese, Cyrillic, Greek, Hebrew, Japanese, Korean, etc., may possibly read right-to-left (rtl). To include chapter titles in these languages, use script-chapter. Chapter titles in script-chapter are wrapped in special HTML markup to isolate rtl script from adjacent left-to-right text. Part of that special markup is a language attribute that browsers can use to assist in the proper display of the script.  Editors may add a prefix to the script that will identify the language.  The prefix is an ISO 639-1 two-character language code followed by a colon: ar: العربية.  Unrecognized codes are ignored and will display in the rendered citation. This field will be displayed following the transliterated title.
 * trans-chapter: If the cited source is in a foreign language, an English translation of the cited chapter title can be given here. This field will be displayed in square brackets within the quotation marks which enclose the chapter field.

Titles containing certain characters will both display and link incorrectly unless those characters are replaced or encoded like this:

Type

 * type: Specifies the type of work cited. Appears in parentheses immediately after the title. Some templates use a default that can be overridden; example: cite press release will show (Press release) by default. Other useful values are Review, Systemic review, Meta-analysis or Original article.

Language

 * language: The language the work is written in, if it is not English. Displayed before the title, enclosed in parentheses and prefixed with in. Do not use icons in this field.  If the source is listed as being in English, then this parameter will be ignored.

Work and publisher

 * work: Used by some templates such as cite web, cite news (where it is aliased to newspaper), cite magazine (aliased to magazine), cite journal (aliased to journal), and others where the citation is usually to a specific item in a larger work, most commonly an article in a website or print periodical, or an episode in a TV series. Do not confuse this with the "publisher" parameter, which is for the publishing company. If the work is notable and has an article in Wikipedia, it should be wiki-linked at first appearance in citations in the article. If the "title" is already linked to externally, do not externally link to the "work".
 * On websites, in most cases "work" is the name of the website (as usually given in the logo/banner area of the site, and/or appearing in the  of the homepage, which may appear as the page title in your browser tab, depending on browser); otherwise use the site's domain name. If the "work" as given by the site/publication would be exactly the same as the name of the publisher, use the domain name; do not falsify the work's name by adding descriptive verbiage like "website of [Publisher]" or "[Publisher]'s Homepage". Capitalize for reading clarity, and omit "www.", e.g. convert "www.veterinaryresourcesuk.com" to "VeterinaryResourcesUK.com". Many journals use highly abbreviated titles when citing other journals (e.g. "J Am Vet Med" for "Journal of the American Veterinary Medical Association") because specialists in the field the journal covers usually already know what these abbreviations mean. Our readers do not, so these abbreviations should always be expanded. If the titled item being cited is part of some other larger work, such as a book, periodical or sub-organization, forming a sub-site at a domain name (e.g., the law school's section of a university's website system), it is usually better to use the name of that more specific work than that of the entire site/system. If the nature of the work and its relation to the site, book or other context in which it is found is complicated or confusing, simply explain the situation after the citation template and before the that closes the citation.


 * publisher: the name of the organization that actually published the source. The field should not include the corporate designation such as "Ltd" or "Inc.", unless some ambiguity would result or the organization is usually known with that designation even in everyday use. "Publisher", "Publishing" and "Publications" can be abbreviated "Pubr.", "Pubg." and "Pubs." respectively, but some templates in this series include a period (full-stop) immediately after this parameter, so the period may have to be omitted; check the output if you abbreviate here. These words are usually safe to omit, but are usefully included where the publisher's name might be confusing. This is most often the case when the publisher's name is something like "Joshua Martin Publications", which without the designation might be mistaken for a co-author. A leading "The" can generally be omitted, again unless confusion might result (e.g., for The International Cat Association, "The" is part of their official acronym, TICA). If the publisher is notable and has an article independent of the "work", the "publisher" parameter can include a wiki-link to that article, but should never externally link to the publisher's website. The "publisher" parameter should not be included either for mainstream, widely-known newspapers, or where it would be the same or mostly the same as the work/site/journal/etc., for example, the "publisher" parameter should be omitted in these examples:
 * Amazon.comAmazon
 * The Aberdeen TimesThe Aberdeen Times
 * USA TodayGannett Company
 * Journal of Physics GIOP Publishing
 * Whether the publisher needs to be included depends on the type of work. Citing sources suggest it should be for books, but not necessarily other works. If the work is self-published, this is a very important fact about potential reliability of the source, and needs to be specified; no consensus exists for the exact value of publisher, but some printed style guides suggest "author". When an exhaustive attempt to discover the name of the publisher (try whois for websites) fails, use publisher to explicitly indicate that this was checked, so other editors do not waste time duplicating your fruitless efforts. Do not guess at the publisher when this information is not clear.


 * location: Geographical place of publication, usually City, Country, or City, U.S. State; simply the city name by itself can be used for world-recognized cities like New York, London (except in articles about Canadian topics), Paris, Tokyo. Simply having a unique name does not mean it is globally recognizable; e.g., many people do not know where Mumbai is, especially if they are old enough that it was called Bombay for much of their lives. If in doubt, be more not less specific, since "Toronto, Canada" and "San Francisco, California" do not actually hurt anything. The location parameter should be omitted when it is implied by the name of the work, e.g. The New York Times. The location parameter should be used when the location is part of the common name but not the actual name of a newspaper. For example, the newspaper commonly known as the New York Daily News is actually Daily News (New York) and can be entered with Daily News New York, which yields Daily News (New York).
 * publication-date: Date of publication when different from the date the work was written. Displays only if year or date are defined and only if different, else publication-date is used and displayed as date. Use the same format as other dates in the article; do not wikilink. Follows publisher; if work is not defined, then publication-date is preceded by "published" and enclosed in parenthesis.
 * via (optional): Name of the content deliverer (when they are not the publisher). via is not a replacement for publisher, but provides additional detail. It may be used when the content deliverer presents the source in a format other than the original, or when the URL provided does not make clear the identity of the deliverer, or as suggested in WP:The Wikipedia Library, e.g. WP:Credo accounts/Citations. See also §Registration or subscription required.

Pages
An editor may use any one of the following parameters in a given citation to refer to the specific page(s) or place in a cited source that contains the information that supports the article text. If more than one of the following parameters are used in the same citation, the error message Extra  or   ( help ) will display in the published citation. When more than one of the following parameters is used in error, page overrides both pages and at; pages overrides at. To resolve the error, remove extra parameters of this type until only one remains in the affected citation.
 * page: page in the cited source containing the information that supports the article text, for example 52.
 * Note: For a hyphenated page, use 1234. This will not only properly display a hyphen, but also reduce the likelihood that an editor/bot will convert this to 1234 by mistake.
 * pages: pages in the cited source containing the information that supports the article text. Separate page ranges with an en dash: –, for example 236–239 . Separate non-sequential pages with a comma, for example 157,159 . The form 461,466–467 is used when you are citing both non-contiguous and sequential pages.
 * Note: CS1 citations do not record the total number of pages in a cited source; do not use this parameter for that purpose.
 * at: place in the cited source containing the information that supports the article text when a page number is not given, is inappropriate or is insufficient. Common examples include column or col., paragraph or para. and section or sec. Depending on the source being cited, other indicators may be appropriate to use with the at parameter including, but not limited to, track, hours, minutes and seconds, act, scene, canto, book, part, folio, stanza, back cover, liner notes, indicia, colophon, dust jacket, etc. Examples include Column 2 or Paragraph 5 or Back cover or Act III, Scene 2.

Edition identifiers

 * edition: Identifies the particular edition of a cited source when the source has more than one edition, such as "2nd", "Revised", etc. Note that this parameter automatically displays " ed." after your entry. For example, Revised third displays as: Revised third ed. The edition parameter can be omitted if there is no content difference between two editions of the same work; e.g. if a book was identically published in the UK and the US except, for example, ISBN number and cover art, it is not necessary to indicate either "UK" or "US" edition; or if citing minute:seconds of a film available in both a regular edition and a "Special Limited Collector's Edition", if the running time and cut are the same, it is not necessary to cite the particular edition.
 * series: When the source is part of a series, such as a book series or a journal where the issue numbering has restarted. For journal series, series should be limited to Original/New Series or First/Second/Third/... Series.
 * volume: For a source published in several volumes. This field is displayed in bold after the title and series parameters. An alternative is to include the volume information in the title parameter after the main title.
 * issue: When the source is part of a series that is published periodically. Aliases: number.

Online sources
Links to sources are regarded as conveniences and are not required, except when citing Web-only sources. There are many digital libraries with works that may be used as sources.
 * Links should be to full versions of the source.
 * Online sources that require payment or subscription may be included per the verifiability policy.

Do not link to:


 * Sites that do not have permission to republish the work or which otherwise violate copyright.
 * Commercial sites such as Amazon, unless no alternative exists.
 * Reviews of the work.
 * Very short extracts such as Google Books snippet view where there is not enough context to verify the content, unless the entire work is also freely available there. (See WP:BOOKLINKS)

Link formats
Links should be kept as simple as possible. For example, when performing a search for a Google Book, the link for Monty Python and Philosophy would look like:


 * https://books.google.com/books?id=NPDgD546-doC&pg=PP1#v=onepage&q&f=false

But can be trimmed to:


 * https://books.google.com/?id=NPDgD546-doC&pg=PP1#v=onepage&q&f=false

or:


 * https://books.google.com/?id=NPDgD546-doC&printsec=frontcover

or:


 * https://books.google.com/?id=NPDgD546-doC (if Google Books does not provide the cover page).

Pages
A direct link to a specific page may be used if supported by the host. For example, the link to page 172 of Monty Python and Philosophy on Google Books:
 * https://books.google.com/?id=NPDgD546-doC&pg=PA172

like so:

If the same source is reused with different pages, separate citations must be created. A way around this problem is to use a short citation, or to provide linked page number citations.

Access date

 * access-date: The full date when the content pointed to by url was last verified to support the text in the article; do not wikilink; requires url; use the same format as other access and archive dates in the citations. It is not required for linked documents that do not change. For example, access-date is not required for links to copies of published research papers accessed via DOI or a published book, but should be used for links to news articles on commercial websites (these can change from time to time, even if they are also published in a physical medium). Note that access-date is the date that the URL was checked to not just be working, but to support the assertion being cited (which the current version of the page may not do). Can be hidden or styled by registered editors. Alias: accessdate.

Icons
URLs with certain filename extensions or URI schemes will apply an icon specific to that file type. This is done through MediaWiki CSS, not these templates.

Web archives
The original link may become unavailable. When an archived version is located, the original URL is retained and archive-url is added with a link to an archived copy of a web page, usually from services like WebCite and the Internet Archive. archive-date must be added to show the date the page was archived, not the date the link was added. When archive-url is used, url and archive-date are required, else an error will show. When an archived link is used, the citation displays with the title linked to the archive and the original link at the end:
 * archive-url
 * archive-date




 * dead-url: To change the order with the title retaining the original link and the archive linked at the end, set no:


 * When the original URL has been usurped for the purposes of spam, advertising, or is otherwise unsuitable, setting unfit or usurped suppresses display of the original URL (but url archive-url are still required).
 * When the original URL has been usurped for the purposes of spam, advertising, or is otherwise unsuitable, setting unfit or usurped suppresses display of the original URL (but url archive-url are still required).

Identifiers
A custom identifier can be specified through

Registration or subscription required
Citations of online sources that require registration or a subscription are acceptable in Wikipedia as documented in Verifiability – Access to sources. As a courtesy to readers and other editors, editors can signal the access restrictions of the external links included in a citation.

Four access levels can be used:
 * Lock-green.svg : the source is free to read for anyone
 * Lock-gray-alt-2.svg : a free registration is required to access the source
 * Lock-gray-alt-2.svg : there are other constraints (such as a cap on daily views) to freely access this source
 * Lock-red-alt.svg : the source is only accessible via a paid subscription

As there are often multiple external links with different access levels in the same citation, these values are attributed to a particular external link.

Access level of url
Links inserted with url are expected to be free to read by default. If not, editors can use one of to indicate the relevant access restriction.
 * subscription
 * registration
 * limited

Access level of identifiers
Links inserted by identifiers such as doi are not expected to offer a free full text by default. If they do, editors can use free (in the case of doi) to indicate the relevant access level. The following identifiers are supported:
 * bibcode with free
 * doi with free
 * hdl with free
 * jstor with free
 * ol with free
 * osti with free

Some identifiers always link to free full texts. In this case, the access level is automatically indicated by the template. This is the case for arxiv, biorxiv, citeseerx, pmc, rfc and ssrn.

Old access parameters
The parameters yes and yes can also be used to indicate the access level of a citation. However, they do not indicate which link they apply to, so editors are encouraged to use registration and subscription instead, when the restriction applies to url. If the restriction applies to an identifier, these parameters should be omitted.

Quote

 * quote: Relevant text quoted from the source; enclosed in quotes. When supplied, the citation terminator (a period by default) is suppressed, so the quote must include any terminating punctuation.

Anchors

 * ref: Creates an anchor for use with Shortened footnotes and parenthetical referencing. These styles use in-text cites with a link that will jump to an anchor created by the CS1 template. Anchors are not enabled by default. (See Harvard citation documentation for details.)
 * harv: Creates an anchor from up to four author last names and the year, of the format, suitable for a ,  etc. Examples:
 * Creates an anchor named  which may be linked from.
 * Creates an anchor named  which may be linked from.
 * Creates an anchor named  which may be linked from.
 * Creates an anchor named  which may be linked from.


 * ID: Creates a custom anchor defined by ID . This is useful where the author and/or date is unknown. The template may be used here to create an anchor suitable for a,  etc. For example,   creates an anchor which may be linked from.

Display options
These features are not often used, but can customize the display for use with other styles.

et al.
et al. is the abbreviation of the Latin et alii (and others). It is used to complete a list of authors of a published work, where the complete list is considered overly long. The term is widely used in English, thus it is not italicized per MOS:FOREIGN.

Printing
When viewing the page, CS1 templates render the URL to the title to create a link; when printing, the URL is printed. External link icons are not printed.

Elements not included
Not all factually accurate pieces of information about a source are used in a Citation Style 1 citation. Examples of information not included:
 * The total number of pages in a cited source
 * The name of the library that provided access to an electronic copy of a cited source
 * The name of the library that owns a physical copy of a cited work
 * The library record and/or shelf location of a physical copy of a cited work

Tools
CS1 templates may be inserted manually or by use of tools:
 * Citoid, a tool built into Visual Editor that attempts to build a full citation based on a URL.  See user guide.
 * RefToolbar is part of the editing tool bar. Version 2.0 does not yet support all templates supported by version 1.0.
 * ProveIt provides a graphical interface for editing, adding, and citing references. It may be enabled per the documentation.
 * Wikipedia citation tool for Google Books
 * DOI Wikipedia reference generator
 * New York Times Wikipedia reference generator
 * Reflinks Adds references to templates while updating/filling-in title/dates/publisher/accessdates etc.
 * reFill open source version of Reflinks
 * Zotero can export citations in Wikipedia-ready format.
 * Citer - Generate shortened footnote or named reference for a given Google Books URL, ISBN, or DOI. Also supports some major news websites.

Error checking:
 * User:Ucucha/HarvErrors is a script that may be enabled to display errors when using Shortened footnotes or parenthetical referencing.

Common issues

 * access-date does not show.
 * If url is not supplied, then access-date does not show; by design.


 * The bare URL shows before the title.
 * If the title field includes a newline or an invalid character then the link will be malformed; see Web links.


 * The title appears in red.
 * If URL is supplied, then the title cannot be wikilinked.


 * The URL is not linked and shows in brackets.
 * The URL must include the URI scheme in order for MediaWiki to recognize it as a link. For example:  vs..


 * A field is truncated.
 * A pipe (&#124;) in the value will truncate it. Use instead.


 * The template markup shows.
 * Double open brackets &#91;&#91; are used in a field without closing double brackets &#93;&#93;.


 * The author shows in brackets with an external link icon.
 * The use of an URL in author-link will break the link; this field is for the name of the Wikipedia article about the author, not a website.


 * Multiple author or editor names are defined and one or more does not show
 * The parameters must be used in sequence, i.e. if last or last1 is not defined, then last2 will not show. By design.


 * page, pages or at do not show.
 * These parameters are mutually exclusive, and only one will show; by design.


 * Too many templates used on one page can also cause server lag problems, causing the page to load slowly or save slowly after an edit has been made.