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:CITESTYLE:

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 (in addition to Wikipedia's own Manual of Style), 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.

Templates

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.

Yes	Indicates that the corresponding tool or gadget can generate the template anytime user wishes. However, this does not mean that the tool or gadget fully supports all parameters or provides an interface for them. In fact, none of the mentioned items do so.
Sometimes	Indicates that the corresponding tool or gadget may or may not generate the corresponding template. For more information, see associated footnote.

General use CS1 templates

Template	Use	Citoid	Citation expander	RefToolbar 2.0	ProveIt	SnipManager
{{Cite arXiv}}	arXiv preprints
{{Cite AV media}}	audio and visual sources				Yes	Yes
{{Cite AV media notes}}	liner notes from albums, DVDs, CDs and similar audio-visual media
{{Cite book}}	books	Yes	Yes	Yes	Yes	Yes
{{Cite conference}}	conference papers				Yes
{{Cite encyclopedia}}	edited collections				Yes
{{Cite episode}}	television or radio programs and episodes				Yes
{{Cite interview}}	interviews
{{Cite journal}}	academic and scientific papers and journals	Yes	Yes	Yes	Yes	Yes
{{Cite magazine}}	magazines and newsletters				Yes
{{Cite mailing list}}	archived public mailing lists
{{Cite map}}	maps
{{Cite news}}	news articles in print, video, audio or web	Yes	Sometimes	Yes	Yes	Yes
{{Cite newsgroup}}	online newsgroups
{{Cite podcast}}	audio or video podcast
{{Cite press release}}	press releases				Yes
{{Cite report}}	unpublished reports by government departments, instrumentalities, operated companies, etc.				Yes
{{Cite serial}}	audio or video serials
{{Cite sign}}	signs, plaques and other visual sources				Yes
{{Cite speech}}	speeches
{{Cite techreport}}	technical reports
{{Cite thesis}}	theses				Yes
{{Cite web}}	web sources not characterized by another template	Yes	Yes	Yes	Yes	Yes

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:

Author (n.d.). "Title". Work. Publisher. Identifiers.

• Without author:

"Title". Work. Publisher. n.d. Identifiers.

(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:

{{cite book |last=Hawking |first=Stephen |last2=Hawking |first2=Lucy |title=George's Secret Key to the Universe}}

Hawking, Stephen; Hawking, Lucy. George's Secret Key to the Universe.

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:

{{cite book |last=Hawking |first=Stephen |author-link=Stephen Hawking |last2=Hawking |first2=Lucy |title=George's Secret Key to the Universe}}

Hawking, Stephen; Hawking, Lucy. George's Secret Key to the Universe.

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

{{cite book |last=Hawking |first=Stephen |author-link=Stephen Hawking |last2=Hawking |first2=Lucy |title=George's Secret Key to the Universe |year=2007}}

Hawking, Stephen; Hawking, Lucy (2007). George's Secret Key to the Universe.

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

{{cite book |title=George's Secret Key to the Universe |year=2007}}

George's Secret Key to the Universe. 2007.

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

|author=<!--Not stated-->

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 {{cite news |work=Weekday Times|author=Weekday Times editors|title=...}}, 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. |author=Commission on Headphone Safety or |author=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 has a Wikipedia article, you may wikilink to that 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. |editor-link= cannot be used to link to an external website.

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.

Translators

A translator may be cited using separate parameters for the translator's last and first name. A single or first translator would use |translator-last= and |translator-first=; subsequent translators would use |translator2-last= and |translator2-first=, |translator3-last= and |translator3-first=, etc.

If a translator has a Wikipedia article, you may wikilink to that Wikipedia article using |translator-link=. If a cited work has multiple translators, you may use |translator2-link=, |translator3-link=, etc. to wikilink to each translator's Wikipedia article. This method is used because |translator-last= and |translator-first= do not allow wikilinking. |translator-link= cannot be used to link to an external website.

Others

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

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. Discouraged in favor of date, except in the rare case that all of the following conditions are met:
    1. the publication-date format in the template is YYYY-MM-DD
    2. the citation requires a CITEREF disambiguator
    3. the template uses |ref=harv or |mode=cs2 or the template is {{citation}}
• orig-year: Original publication year, for display (in square brackets) after the date (or year). For clarity, please supply specifics, for instance orig-year=first published 1859 or orig-year=composed 1904. This parameter displays only if there is a value for date (or year).

When a source does not have a publication date, use |date=n.d. or |date=nd

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 convention. In cases where the date as expressed in the source is not compatible with the template software, the citation should be created without using a template.
• Do not wikilink.
• Access and archive dates in references should be in either the format used for publication dates, or YYYY-MM-DD.

Date compliance with Wikipedia's Manual of Style

CS1 uses Wikipedia: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.

CS1 compliance with Wikipedia:Manual of Style/Dates and numbers

section	compliant	comment
Acceptable date formats table	yes	Exceptions: linked dates not supported; sortable dates not supported ({{dts}} etc.); proper name dates not supported with the exception of 'Christmas YYYY'; shortened month names longer than three characters or with terminating periods not supported
Unacceptable date formats table	yes
Consistency	yes	Article-level restrictions are beyond the scope of CS1 CS1/CS2 templates follow the format specified by the article's {{use dmy dates}} or {{use mdy dates}} templates; see Auto-formatting citation template dates
Strong national ties to a topic	no
Retaining existing format	no
Era style	no	Dates earlier than 100 not supported. Wikipedia does not treat ancient manuscripts as sources that can be cited directly; a specific, modern, published edition is what goes in the source citation. Thus, the date of the source actually consulted should be provided in |date=, and the date of the ancient source may be provided in |orig-year=; the format of the orig-year value is not checked for errors.
Julian and Gregorian calendars	limited	Julian prior to 1582; Gregorian from 1582; assumes Gregorian in the overlap period of 1582 – c. 1923
Ranges	yes	Exceptions: does not support the use of – or   does not support dates prior to 100; does not support solidus separator (/) does not support " to " as a date separator does not support YYYY–YY where the two-digit year is less than 13 (change to YYYY–YYYY to eliminate the error message)
Uncertain, incomplete, or approximate dates	yes	Exceptions: does not support {{circa}} or {{floruit}}; does not support dates prior to 100; Supports c. only with a single year value (no ranges or day/month combinations).
Days of the week	no
Seasons	limited	CS1 capitalizes seasons used as dates in citations, in line with external style guides
Decades	no
Centuries and millennia	no
Abbreviations for long periods of time	no

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 = July 4, 1997b) or the year parameter (year = 1997b).

Auto-formatting citation template dates

Citation Style 1 and 2 templates automatically render dates (|date=, |access-date=, |archive-date=, etc) in the style specified by the article's {{use dmy dates}} or {{use mdy dates}} template. Because it is allowed by WP:MOSDATES, the CS1/CS2 templates can automatically format dates in a variety of styles. Editors may choose how CS1/CS2 templates render dates by the use of |cs1-dates=<keyword> in the article's {{use xxx dates}} template.

cs1-dates= keywords

keyword	definition
l	long-form publication and access- / archive-dates; this is the default case when |cs1-dates= is omitted or empty
ll
ls	long-form publication dates; abbreviated access- / archive-dates
ly	long-form publication dates; year-initial numeric access- / archive-dates (ymd)
s	abbreviated publication and access- / archive-dates
ss
sy	abbreviated publication dates; year-initial numeric access- / archive-dates (ymd)
y	year-initial numeric publication, access- and archive-dates (ymd); use of these keywords may conflict with MOS:DATEUNIFY; cs1|2 cannot reformat Month YYYY, Season YYYY, date-ranges of any form, or Julian calendar dates into ymd format
yy

Example: to have the CS1/CS2 templates in an article render their publication dates in the long form (fully spelled-out month names) with access-/archive-dates rendered in short form (abbreviated month names), write:

{{use dmy dates|date=December 2024|cs1-dates=ls}}

This documentation page has {{use dmy dates|date=December 2024|cs1-dates=ls}} at the top of this section so this cs1 template will render with a long-form publication date and an abbreviated access date:

{{cite web |title=Example Webpage |url=//example.com |website=Example |date=Oct 31, 2017 |access-date=2017-12-05}}

"Example Webpage". Example. 31 October 2017. Retrieved 5 Dec 2017.

This global setting may be overridden in individual CS1/CS2 templates by use of |df=; abbreviated date forms are not supported by |df=.

: CS1/CS2 auto-date formatting does not apply when previewing an article section that does not contain a {{use xxx dates}} template.

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 {{cite news}}, {{cite journal}}, {{cite web}}, {{cite conference}}, and {{cite podcast}}, 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 does not attempt to emulate any stylistic flourishes used by the cited source's publisher, such as ALL-CAPS, all-lower-case, Template:Sm, 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: |script-title=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: |at=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: |script-title=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:

Character	Must be replaced with
newline	space
[	[
]	]
|	|

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

Further information: WP:CITEHOW

• 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 (given in the "title" parameter) found in a larger work (this "work" parameter), 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 <title>...</title> 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 </ref> 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 for mainstream, widely-known news sources, for major academic journals, or where it would be the same or mostly the same as the work. For example, the "publisher" parameter should be omitted in these examples:

|work=[[Amazon.com]]|publisher=Amazon

|website=[[CNN]]|publisher=[[WarnerMedia]]

|newspaper=The Aberdeen Times|publisher=The Aberdeen Times

|newspaper=[[USA Today]]|publisher=[[Gannett Company]]

|journal=[[Journal of Physics G]]|publisher=[[IOP Publishing]]

Do not use the "publisher" parameter as an alternative to the "work" parameter (in particular, do not leave "work" empty with "publisher" non-empty in order to avoid rendering a website's name in italics; a website is a publication and thus its name should be rendered in italics – e.g., as CNN in the example above). Whether the publisher needs to be included depends on the type of work. Wikipedia: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= in such a case, 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=<!--Unspecified by source.--> 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, US State. 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 Sydney Morning Herald. 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 and can be entered with |newspaper=Daily News |location=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

volume=, |issue=, |page(s)=

template	volume=	issue=	page(s)=
{{citation}}	Yes	Yes	Yes
{{cite arXiv}}	No	No	Yes
{{cite AV media}}	Yes	No	No
{{cite AV media notes}}	No	No	Yes
{{cite bioRxiv}}	No	No	Yes
{{cite book}}	Yes	No	Yes
{{cite citeseerx}}	No	No	Yes
{{cite conference}} (as a book)	No	No	Yes
{{cite conference}} (as a journal)	Yes	Yes	Yes
{{cite encyclopedia}}	Yes	No	Yes
{{cite episode}}	No	Yes	No
{{cite interview}}	Yes	Yes	Yes
{{cite journal}}	Yes	Yes	Yes
{{cite magazine}}	Yes	Yes	Yes
{{cite mailing list}}	No	No	No
{{cite map}} (as book)	Yes	No	Yes
{{cite map}} (as journal or magazine)	Yes	Yes	Yes
{{cite news}}	Yes	Yes	Yes
{{cite newsgroup}}	No	No	No
{{cite podcast}}	No	No	No
{{cite press release}}	No	No	Yes
{{cite report}}	Yes	No	Yes
{{cite serial}}	No	No	No
{{cite sign}}	No	No	No
{{cite speech}}	No	No	No
{{cite ssrn}}	No	No	Yes
{{cite techreport}}	Yes	No	Yes
{{cite thesis}}	Yes	No	Yes
{{cite web}}	No	No	Yes

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 |pages= or |at= (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 |page=52 .
  • Note: For a hyphenated page, use |page=12{{hyphen}}34. This will not only properly display a hyphen, but also reduce the likelihood that an editor/bot will convert this to |pages=12{{endash}}34 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 |pages=236–239 . Separate non-sequential pages with a comma, for example |pages=157,159 . The form |pages=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 |at=Column 2 or |at=Paragraph 5 or |at=Back cover or |at=Act III, Scene 2.

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 {{sfn}}, or {{rp}} to provide linked page number citations.

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, |edition=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, First/Second/Third/... Series, or similar.
• 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.

External links

• url: Adds a link to the title
• chapter-url: Adds a link to the chapter.
• format: Format of the document at its URL (e.g., PDF, xls, etc.) Do not specify for HTML as it is implied as the default. Several URI schemes and filename extensions will show an icon— these icons have no alt text and do not meet accessibility standards. Do not use this parameter for completely different purposes, with annotations such as "fee required" or "reprint"; its intent is to notify readers what the file format is (e.g. in case some browsers might have trouble with it, or some might prefer to save the link to disk rather than open it in the browser). Access restrictions can be shown using |subscription= or |registration=, see Registration or subscription required. Other notes about reprintings, etc., should be placed after the template, and before </ref>.

Online sources

Main articles: WP:External links and WP:Citing 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:

Main article: WP:LINKSTOAVOID

• 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:

|page=[https://books.google.com/?id=wPQelKFNA5MC&pg=PA172 172]

Special characters

URLs must begin with a supported URI scheme. http:// and https:// will be supported by all browsers; however, ftp://, gopher://, irc://, ircs://, mailto: and news: may require a plug-in or an external application and should normally be avoided. IPv6 host-names are currently not supported.

If URLs in citation template parameters contain certain characters, then they will not display and link correctly. Those characters need to be percent-encoded. For example, a space must be replaced by %20. To encode the URL, replace the following characters with:

sp	"	'	<	>	[	]	{	|	}
%20	%22	%27	%3c	%3e	%5b	%5d	%7b	%7c	%7d

Single apostrophes do not need to be encoded; however, unencoded multiples will be parsed as italic or bold markup. Single curly closing braces also do not need to be encoded; however, an unencoded pair will be parsed as the double closing braces for the template transclusion.

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

Main page: Help:External link 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

Further information: Wikipedia:Link rot

• archive-url
• archive-date

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: "Monty Python and Philosophy". Archived from the original on 1 May 2013.

• url-status: To change the order with the title retaining the original link and the archive linked at the end, set |url-status=live:

"Monty Python and Philosophy". Archived from the original on 1 May 2013.

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

• dead-url: Deprecated. Use |url-status= instead.

Identifiers

These identifiers create links and are designed to accept a single value. Using multiple values or other text will break the link and/or invalidate the identifier. In general, the parameters should include only the variable part of the identifier, e.g. rfc=822 or pmc=345678.

When an URL is equivalent to the link produced by the corresponding identifier (such as a DOI), don't add it to any URL parameter but use the appropriate identifier parameter, which is more stable and may allow to specify the access status. The |url= parameter or title link can then be used for its prime purpose of providing a convenience link to an open access copy which would not otherwise be obviously accessible.

• arxiv: arXiv identifier; for example: arxiv=hep-th/9205027 (before April 2007) or arxiv=0706.0001 (April 2007 – December 2014) or arxiv=1501.00001 (since January 2015). Do not include extraneous file extensions like ".pdf" or ".html".
• asin: Amazon Standard Identification Number; if first character of asin value is a digit, use isbn. Because this link favours one specific distributor, include it only if standard identifiers are not available. Example asin=B00005N5PF
  • asin-tld: ASIN top-level domain for Amazon sites other than the US; valid values: au, br, ca, cn, co.jp, co.uk, de, es, fr, it, mx
• bibcode: Bibcode; used by a number of astronomical data systems; for example: 1974AJ.....79..819H. Comment: Techies are aware of the 2019 switch from old to new ADS URLs: the old URLs should continue working after October 2019 even though deprecated; see the April/May 2019 and June 2019 discussions.
• biorxiv: bioRxiv id, a 6-digit number at the end of the biorXiv URL (e.g. 078733 for http://biorxiv.org/content/early/2016/10/01/078733 or https://dx.doi.org/10.1101/078733)
• citeseerx: CiteSeerX id, a string of digits and dots found in a CiteSeerX URL (e.g. 10.1.1.176.341 for http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.176.341 )
• doi: Digital object identifier; for example: 10.1038/news070508-7. It is checked to ensure it begins with (10.).
  • doi-broken-date: Date the DOI was found to be non-working at https://dx.doi.org. Use the same format as other dates in the article. Alias: doi-inactive-date
• eissn: International Standard Serial Number for the electronic media of a serial publication; eight characters may be split into two groups of four using a hyphen, but not an en dash or a space; example eissn=1557-2986 Alias: EISSN
• hdl: Handle System identifier for digital objects and other resources on the Internet; example hdl=20.1000/100 Alias: HDL
• isbn: International Standard Book Number; for example: 978-0-8126-9593-9. (See Wikipedia:ISBN and ISBN § Overview.) Hyphens in the ISBN are optional, but preferred. Use the ISBN actually printed on or in the book. Use the 13-digit ISBN – beginning with 978 or 979 – when it is available. If only a 10-digit ISBN is printed on or in the book, use it. ISBNs can be found on the page with the publisher's information – usually the back of the title page – or beneath the barcode as a number beginning with 978 or 979 (barcodes beginning with any other numbers are not ISBNs). For sources with the older 9-digit SBN system, prefix the number with a zero; thus, SBN 902888-45-5 should be entered as |isbn=0-902888-45-5. Do not convert a 10-digit ISBN to 13-digit by just adding the 978 prefix; the last digit is a calculated check digit and just making changes to the numbers will make the ISBN invalid. This parameter should hold only the ISBN without any additional characters. It is checked for length, invalid characters – anything other than numbers, spaces, and hyphens, with "X" permitted as the last character in a 10-digit ISBN – and the proper check digit. Alias: ISBN
• ismn: International Standard Music Number; for example: 979-0-9016791-7-7. Hyphens or spaces in the ISMN are optional. Use the ISMN actually printed on or in the work. This parameter should hold only the ISMN without any additional characters. It is checked for length, invalid characters – anything other than numbers, spaces, and hyphens – and the proper check digit. Alias: ISMN
• issn: International Standard Serial Number; eight characters may be split into two groups of four using a hyphen, but not an en dash or a space; example issn=2049-3630 Alias: ISSN
• jfm: Jahrbuch über die Fortschritte der Mathematik; example jfm=53.0144.01
• jstor: JSTOR reference number; for example: jstor=3793107 will generate JSTOR 3793107.
• lccn: Library of Congress Control Number. When present, alphabetic prefix characters are to be lower case; example lccn=2004042477
• mr: Mathematical Reviews; example mr=630583
• oclc: OCLC; WorldCat's Online Computer Library Center; example oclc=9355469
• ol: Open Library identifier; do not include "OL" in the value; example ol=7030731M
• osti: Office of Scientific and Technical Information; example osti=4367507
• pmc: PubMed Central; use article number for open repository full-text of a journal article, e.g. pmc=345678. Do not include "PMC" in the value. See also the pmid parameter, below; these are two different identifiers.
  • embargo: Date that pmc goes live; if this date is in the future, then pmc is not linked until that date.
• pmid: PubMed; use unique identifier; example pmid=17322060 See also the pmc parameter, above; these are two different identifiers.
• rfc: Request for Comments; example rfc=3143
• ssrn: Social Science Research Network; example ssrn=1900856
• zbl: Zentralblatt MATH; example zbl=0472.53010 For zbMATH search results like JFM 35.0387.02 use jfm=35.0387.02

A custom identifier can be specified through

• id: A unique identifier, used where none of the specialized identifiers are applicable; wikilink or use a template as applicable. For example, |id=NCJ 122967 will append "NCJ 122967" at the end of the citation. You can use templates such as |id={{NCJ|122967}} to append NCJ 122967 instead.

Registration or subscription required

Tracked in Phabricator
Task T225430

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. : access icons do not display correctly for editors who use Modern skin.

There are four access levels split between the url-holding parameters and the identifier parameters.

Access level of url-holding parameters

There are several url-holding parameters. Each may be marked with a access icon. Links inserted with any of the url-holding parameters are expected to be free-to-read by default, so |url-access=free is not valid. For a URL that is not free-to-read, editors may use the matching access-icon parameter with the appropriate keyword.

url-holding parameter access icons

url parameter	access icon parameter	supported keywords
url=	url-access=	subscription – – the source is only accessible via a paid subscription registration – – a free registration is required to access the source limited – – there are other constraints (such as a cap on daily views) to freely access this source
article-url=	article-url-access=
chapter-url=	section-url-access=
contribution-url=	section-url-access=
entry-url=	section-url-access=
map-url=	section-url-access=
section-url=	section-url-access=

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 |doi-access=free (in the case of |doi=) to indicate the relevant access level.

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=.

identifier parameter access icons

url parameter	access icon parameter	supported keywords
bibcode=	bibcode-access=	free – – the source is free to read for anyone (not supported by |url-access=)
doi=	doi-access=
hdl=	hdl-access=
jstor=	jstor-access=
ol=	ol-access=
osti=	osti-access=

Old access parameters

The parameters |registration=yes and |subscription=yes are no longer supported. They were used to indicate the access level of a citation. They were deprecated because they did not indicate the link to which they applied. Editors should use |url-access=registration or |url-access=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.)
• |ref=harv: Creates an anchor from up to four author last names and the year, of the format CITEREFlastname(s)year, suitable for a {{harv}}, {{sfn}} etc. Examples:

{{cite book |first=Gary L. |last=Hardcastle |title=Monty Python and Philosophy |year=2006 |ref=harv}}

Creates an anchor named CITEREFHardcastle2006 which may be linked from {{harv|Hardcastle|2006|pp=12-34}}.

{{cite book |first=Gary L. |last=Hardcastle |first2=George A. |last2=Reisch |title=Monty Python and Philosophy |year=2006 |ref=harv}}

Creates an anchor named CITEREFHardcastleReisch2006 which may be linked from {{harv|Hardcastle|Reisch|2006|pp=12-34}}.

• |ref=ID: Creates a custom anchor defined by ID. This is useful where the author and/or date is unknown. The {{harvid}} template may be used here to create an anchor suitable for a {{harv}}, {{sfn}} etc. For example, ref={{harvid|Monty Python and Philosophy|2006}} creates an anchor which may be linked from {{harv|Monty Python and Philosophy|2006|pp=12-34}}.

Display options

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

• mode: Sets element separator, default terminal punctuation, and certain capitalization according to the value provided. For |mode=cs1, element separator and terminal punctuation is a period (.); where appropriate, initial letters of certain words are capitalized ('Retrieved...'). For |mode=cs2, element separator is a comma (,); terminal punctuation is omitted; where appropriate, initial letters of certain words are not capitalized ('retrieved...'). To override default terminal punctuation use postscript.
• author-mask: Replaces the name of the first author with em dashes or text. Set author-mask to a numeric value n to set the dash n em spaces wide; set author-mask to a text value to display the text without a trailing author separator; for example, "with". You must still include the values for all authors for metadata purposes. Primarily intended for use with bibliographies or bibliography styles where multiple works by a single author are listed sequentially such as shortened footnotes. Do not use in a list generated by {{reflist}}, <references /> or similar as there is no control of the order in which references are displayed. You can also use editor-mask and translator-mask in the same way. Mask parameters can take a number in the name of the parameter (e.g. |authorn-mask=) to specify which author the mask should apply to.
• display-authors: Controls the number of author names that are displayed when a citation is published. To change the displayed number of authors, set display-authors to the desired number. For example, |display-authors=2 will display only the first two authors in a citation. By default, all authors are displayed. |display-authors=etal displays all authors in the list followed by et al. Aliases: displayauthors.
• display-editors: Controls the number of editor names that are displayed when a citation is published. To change the displayed number of editors, set display-editors to the desired number. For example, |display-editors=2 will display only the first two editors in a citation. By default, all editors are displayed. |display-editors=etal displays all editors in the list followed by et al. Aliases: displayeditors.
• last-author-amp: Switches the separator between the last two names of the author list to space ampersand space ( & ) when set to y, yes, or true. Example: |last-author-amp=yes
• postscript: Controls the closing punctuation for a citation; defaults to a period (.); for no terminating punctuation, specify |postscript=none – leaving |postscript= empty is the same as omitting it, but is ambiguous. Additional text or templates beyond the terminating punctuation may generate an error message. |postscript= is ignored if quote is defined.

et al.

et al. is the abbreviation of the Latin ('and others'). It is used to complete a list of authors of a published work, where the complete list is considered overly long. The abbreviation 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

Main page: Help:Citation 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 – generates 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.

TemplateData

This section documents interactions between WP:TemplateData and tools which use that data to edit Wikipedia such as VisualEditor and bots. Before making changes to the TemplateData be aware of these interactions.

User:InternetArchiveBot

• If an argument is set to "required" the argument will be added to all templates edited by IABot. This including adding empty arguments. For example when |website= is "required" IABot makes the following edit: [1].

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: www.example.org vs. http://www.example.org.

A field is truncated.

A pipe (|) in the value will truncate it. Use {{!}} instead.

The template markup shows.

Double open brackets [[ are used in a field without closing double brackets ]].

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.

See also

• Help:Citation Style 2