Help:Cite

Cite makes it possible to add footnotes to a page.

See Extension:Cite for technical details.

Usage

The basic concept of the <ref> tag is that it inserts the text enclosed by the ref tags as a footnote in a designated section, which you indicate with the placeholder tag <references />. This format cannot be used interchangeably with the older format — you must pick one or the other.

Additional placeholder tags <references /> can be inserted in the text, and all <ref> tags up to that point will be inserted there.

If you forget to include <references /> in the article, the footnotes will not disappear, but the references will be displayed at the end of the page.

This page itself uses footnotes, such as the one at the end of this sentence. If you view the source of this page by clicking "Edit this page", you can see a working example of footnotes.

Wikitext	Rendering
The Sun is pretty big.<ref>E. Miller, ''The Sun'', (New York: Academic Press, 2005), 23-5.</ref> The Moon, however, is not so big.<ref>R. Smith, "Size of the Moon", ''Scientific American'', 46 (April 1978): 44-6.</ref> ==Notes== <references />	The Sun is pretty big. The Moon, however, is not so big. Notes

Multiple uses of the same footnote

To give a footnote a unique identifier, use <ref name="name">. You can then refer to the same footnote again by using a ref tag with the same name. The text inside the second tag doesn't matter, because the text already exists in the first reference. You can either copy the whole footnote, or you can use a terminated empty ref tag that looks like this: <ref name="name" />.

In the following example, the same source is cited three times.

Wikitext

Result

This is an example of multiple references to the same footnote.<ref name="multiple">Remember that when you refer to the same footnote multiple times, the text from the first reference is used.</ref> Such references are particularly useful when citing sources, if different statements come from the same source.<ref name="multiple" /> Any reused tag should not contain extra content, that will spawn an error. Only use empty tags in this role. A concise way to make multiple references is to use empty ref tags, which have a slash at the end. Although this may reduce redundant work, please be aware that if a future editor removes the first reference, this will result in the loss of all references using the empty ref tags.<ref name="multiple" /> ==Notes== <references />

This is an example of multiple references to the same footnote. Such references are particularly useful when citing sources, if different statements come from the same source. Any reused tag should not contain extra content, that will spawn an error. Only use empty tags in this role. A concise way to make multiple references is to use empty ref tags, which have a slash at the end. Although this may reduce redundant work, please be aware that if a future editor removes the first reference, this will result in the loss of all references using the empty ref tags. Notes

Note that identifiers used in the name attribute require alphabetic characters; solely relying on numerals will generate an error message. The quotes are optional unless the name includes a space, punctuation or other mark. It is recommended that names be kept simple and restricted to the ASCII character set.

Merging two texts into a single reference

A typical Wikisource issue are references that span multiple pages in the source material. These can be merged using a <ref name="name"> tag for the first part of the reference, and tagging the following parts with a tag <ref follow="name"> using the same name.

Example:

Wikitext

Result

This is an example of merging multiple texts into the same footnote.<ref name="main">Remember that all the texts will be included into the reference containing the name="…" attribute.</ref> <ref follow="main">Simply include the text to be merged into the first &lt;ref name="…"> reference with a tag &lt;ref follow="…">. This paragraph is included into a similar tag and it will be merged into the reference in former paragraph.</ref> ==References== <references/>

This is an example of merging multiple texts into the same footnote. References

When using this syntax into Page: namespace, take care that the ref follow part of the footnote is transcluded too into the same ns0 page, where the first part of footnote is transcluded. Use appropriately section tags to get this result. To also remind users that reference names should not solely be numbers, eg. <ref name="p32"> and <ref follow="p32">.

The <references /> tag

The <references /> tag inserts the text of all the citations which have defined in <ref> tags up to that point in the page. For example, based on the citations above, there should be reference for the note group.

Wikitext	Result
<references group="note"/>

The reference list can have a responsive width (displaying in some cases the references in several columns). In that case, the responsive attribute is used to configure that behavior. On wikis with the default configuration, this will happen on every page; on others, you need to activate it.

In some language editions of Wikipedia, long reference lists may be placed using the template {{Reflist}}, which incorporates <references />. It provides an optional parameter to display the reference list in multiple columns. For instance, the English, Hindi and Interlingua Wikipedias use the CSS selector references-small to make the reference text smaller than normal text.

Using templates in this way is strongly discouraged, for compatibility, performance, and functionality reasons.

If a page includes more than one <references /> list, each list includes the <ref> tags defined after the previous references list. If these references lists are produced by templates, each one lists the ref tags defined before the first references list, and there is an error message saying that there is a ref tag but not a references list.

Grouped references

This may be disabled by $wgAllowCiteGroups = false; if desired.

The following example generates separate reference lists for citations and miscellaneous footnotes:

Wikitext	Result
According to scientists, the Sun is pretty big <ref>E. Miller, ''The Sun'', (New York: Academic Press, 2005), 23-5.</ref> In fact, it is very big <ref group="footnotes"> Take their word for it. Don't look directly at the sun!</ref> ==Notes== <references group="footnotes" /> ==References== <references />	According to scientists, the Sun is pretty big In fact, it is very big Notes References

The anonymous group works as before, while references destined for the named group will only show up in the designated <references /> element.

Note that identifiers used in the group attribute require alphabetic characters; solely relying on numerals will generate an error message. The quotes are optional unless the name includes a space, punctuation or other mark. It is recommended that names be kept simple and restricted to the ASCII character set.

Citing different parts of the same source

When several parts from the same work are used as references in an article, you can cluster them in the reference section. This gives readers a way to identify which references originate from the same source. It also allows you to cite different parts of the same source without repeating the entire source every time.

Wikitext	Result
According to scientists, the Sun is pretty big. <ref name="Miller">E. Miller, ''The Sun'', (New York: Academic Press, 2005)</ref> In fact, it is very big. <ref extends="Miller">p. 123</ref> Take their word for it. Don't look directly at the sun! <ref extends="Miller">p. 42</ref> ==References==	According to scientists, the Sun is pretty big. [1] In fact, it is very big. [1.1] Take their word for it. Don't look directly at the sun! [1.2] References 1. E. Miller, The Sun, (New York: Academic Press, 2005)    1.1 ↑ p. 123    1.2 ↑ p. 42

Note that this feature doesn't yet work on wikis outside the beta cluster, which is why the above example is a mock.

Separating references from text

In-text references make it easy to copy the text to another page; on the other hand, they make it hard to read. References containing a lot of data, quotes or elaborate citation templates can make up a significantly larger fraction of the source than the text that will actually be visible. To avoid this, recent versions of the extension allow moving some or all of the references into the <references /> section, to the place where they will actually appear to the reader.

Wikitext	Result
According to scientists, the Sun is pretty big.<ref name="miller" /> The Moon, however, is not so big.<ref name="smith" /> ==Notes== <references> <ref name="miller">E. Miller, ''The Sun'', (New York: Academic Press, 2005), 23-5.</ref> <ref name="smith">R. Smith, "Size of the Moon", ''Scientific American'', 46 (April 1978): 44-6.</ref> </references>	According to scientists, the Sun is pretty big. The Moon, however, is not so big. Notes

Thus, the code above will have the same output as the first example above, although the numbering and order of the references will not in general be the same.

Substitution and embedded parser functions

Since Cite's <ref> tag is parsed before MediaWiki's parser functions (e.g. {{#ifexpr:…}}) or variables (e.g. {{PAGENAME}}) or before subst:</>, these will not work inside of citation references. Instead, you have to use the magic word {{#tag:…}}.

Wikitext	Result
Foo <ref>This is not working, see {{cite journal|url=https://www.google.com |title=Search |author= |date= |accessdate={{subst:#time:Y-m-d|now}}}}</ref> bar baz… Foo{{#tag:ref|Whereas this does, see {{cite journal|url=https://www.google.com |title=Search |author= |date= |accessdate={{subst:#time:Y-m-d|now}}}}}} bar baz… <references />	Foo bar baz… Foo bar baz…

Adding an automatic heading before the references list

Up to MediaWiki 1.28, one could use the system message MediaWiki:Cite references prefix to define a wiki-wide heading which would be automatically inserted before each references list. In MediaWiki 1.29, this system message was removed. A hacky way to enter a headline now is to add the following code to MediaWiki:Common.js:

$(document).ready(function(){
    $('.mw-references-wrap').before('<h2>References</h2>');
});

If you only need a text heading (no link or other active elements) you could add the following to MediaWiki:common.css (Chrome 4, IE9, FF 3.5, Safari 3.1, Opera 7):

.mw-references-wrap::before {
  content: "Blue references";
  color: #0645ad;
  text-decoration: none;
  background: none;
  font-style: italic;
  font-size: 100%;
  font-weight: bold;
  line-height: 1.6;
  direction: ltr;
  font-family: sans-serif;
}

Customization

The format of the output of <ref> and <references> is almost completely customizable through MediaWiki messages, that can be modified, for example, through the MediaWiki namespace depending on the configuration of the wiki.

For a list of messages that control the output of <ref> and <references> and the values, if any, that are passed to them ($1, $2, $3 ...), see an up-to-date listing of the default values that can be obtained directly from MediaWiki.

Incomplete list

• cite_reference_link_key_with_num
  1. key
  2. num
• cite_reference_link_prefix
• cite_reference_link_suffix
• cite_references_link_prefix
• cite_references_link_suffix
• cite_reference_link
  1. ref ID
  2. backlink ID
  3. count to display
• cite_references_link_one
  • Used to format the source list that <references /> outputs, it configures 3 things: the backlink ID, the ref ID, and text of note.
  1. backlink ID - used for creating the number order of the source list.
  2. ref ID - used to link back to the actual reference in the text, this is where you can configure the <bold>^</bold> symbol
  3. text of note - text used above describing the source info
• cite_references_link_many
  1. backlink ID
  2. list of links
  3. text of note
• cite_references_link_many_format
  1. ref ID
  2. numeric value to use as a backlink
  3. custom value (as defined in cite_references_link_many_format_backlink_labels to use as a backlink)
• cite_references_link_many_format_backlink_labels
• cite_references_link_many_sep
• cite_references_link_many_and
• cite_references_suffix

Set references to use ^ and letters

To replace the default uparrow (↑) with caret (^), modify the following system messages. All of these pages can be found on Special:AllMessages.

MediaWiki:Cite references link one

From	To
<li id="$1"$4><span class="mw-cite-backlink">[[#$2|↑]]</span> $3</li>	<li id="$1"$4><span class="mw-cite-backlink">[[#$2|^]]</span> $3</li>

MediaWiki:Cite references link many

From	To
<li id="$1"$4><span class="mw-cite-backlink">↑ $2</span> $3</li>	<li id="$1"$4><span class="mw-cite-backlink">^ $2</span> $3</li>

MediaWiki:Cite references link many format

Replacing $2 with $3 changes the links from 1.0, 1.1, 1.2 to a, b, c etc…

From	To
<sup>[[#$1|$2]]</sup>	<sup>[[#$1|$3]]</sup>

Searching for these pages for the first time will result in no matches. Simply click "Create this page" to edit the code. The changes will not show up until a page with references is rebuilt.

Set reference and reference number highlighting

Starting with MW 1.26 the selectors for highlighting are now incorporated into Cite/modules/ext.cite.css.Thus the CSS code below no longer needs to be added manually.

Add the following code to the MediaWiki:Common.css page.

/* make the Cite extension list of references look smaller and highlight clicked reference in blue */
ol.references { font-size: 90%; }
ol.references li:target { background-color: #ddeeff; }
sup.reference:target { background-color: #ddeeff; }

Error messages

If the ‎<ref> or ‎<references /> tags are used incorrectly, the Cite extension will add an error message to the page. These messages will usually be in . This section lists the error messages and explains how to fix the problems.

Message	Problem	Solution
Messages in the body of the article
Invalid <ref> tag; refs with no name must have content	There is no content between the ‎<ref>...‎</ref> tags.	Either put content between the ‎<ref> tags (‎<ref>content‎</ref>), or (if you're reusing a named reference that's been defined elsewhere in the article) use a single tag ‎<ref name="ref_name" />.
The opening <ref> tag is malformed or has a bad name	A named reference has a malformed name.	This is produced by a construct like ‎<ref />, which makes no sense. As above, either create a full reference (‎<ref>content‎</ref>) or give the tag a name (‎<ref name="ref_name" />).
Invalid parameter in <ref> tag	A ‎<ref> tag has too many parameters	You can only specify two parameters, name= and group=. You can't, for instance, format a reference with ‎<ref style="color:red;">content‎</ref>, or give it an id.
Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title	The name of the reference is a pure number. To avoid naming conflicts (as unnamed references are automatically assigned numbers as names) this is not allowed.	Rename the reference to contain at least one letter (e.g. ‎<ref name="foo" /> instead of ‎<ref name="123" />). It's good practice to give references meaningful names anyway. Make sure that when changing the name you update all the tags that refer to that reference!
Closing </ref> missing for <ref> tag	A reference is missing the closing ‎</ref>.	Make sure that you are either using a closed pair of tags (‎<ref>content‎</ref>), or one single tag with a forward slash at the end to mark it as a single tag (‎<ref />)
Messages at the end of the article
Invalid <ref> tag; no text was provided for refs named foo	A single ref tag named "foo" (‎<ref name="foo" />) was invoked, but there is no full reference named "foo" (‎<ref name="foo">content‎</ref>) from which to get the reference text.	You may have misspelt the reference name, or used special characters that look the same but are actually different. For instance, ‎<ref name="foo-bar">content‎</ref> and ‎<ref name="foo–bar" /> are not the same: one contains a hyphen while the other uses an ndash. To avoid this sort of error, try to stick to the characters available on the standard keyboard. Alternatively, the full reference may have been removed from the article with other content. In this case the text of the reference will be available in the page history, and you can convert the single ‎<ref /> tag into a full reference.
MediaWiki:Cite error references invalid input (removed)	The ‎<references /> tag is malformed.	You need to ensure that the ‎<references /> tag is properly formed.
Invalid parameter in <references> tag	Parameters such as style= or id= were passed to the ‎<references /> tag.
MediaWiki:Cite error references invalid parameters group (removed)	The ‎<references /> tag is malformed.
Cite error: ‎<ref> tags exist, but no ‎<references /> tag was found	The ‎<references /> tag was not included at the end of the article.	Add the ‎<references /> tag at the bottom of the article, below the last set of |ref= tags.
	The ‎<ref> tag immediately before ‎<references /> does not have a closing ‎</ref>.	Fix the ‎<ref> tag as explained above
	There are ‎<ref>...‎</ref> tags after ‎<references />.	Move the ‎<references /> tag (or the {{reflist}} template) to below the last reference.
	The use of ‎<ref>...‎</ref> tags followed by a ‎<references /> tag occurs more than once on the same page, but the ‎<references /> tag is produced by a template (e.g. {{reflist}}).	There is no solution other than avoiding the use of a template if possible.
	Another tag extension used in the same page before the ‎<references /> tag is buggy (calls Parser->parse() instead of Parser->recursiveTagParse()).	Update/fix the buggy tag extension.
Ran out of custom backlink labels. Define more in the MediaWiki:Cite references link many format backlink labels message.	A named reference was used more than 702 times, thereby exhausting the list of available labels ("a", "b"... "aa", "ab"... "zy", "zz").	It should probably never be necessary to cite one source this many times. Consider whether some cites can be combined or removed, or edit MediaWiki:Cite references link many format backlink labels to add additional labels (maybe "aaa", "aab", etc).
<ref> tags exist for a group named "$1", but no corresponding <references group="$1"/> tag was found	The group parameter was used in a reference, but the corresponding ‎<references /> tag was not included with a group parameter	Make sure that there is a ‎<references /> tag on the page with the appropriate |group= parameter set.
	The reference immediately before ‎<references /> does not have a closing ‎</ref>.	Fix as for normal ‎<references /> tags as explained above.
	There are ‎<ref>...‎</ref> tags using a group after ‎<references />.
Invalid <ref> tag; name "$1" defined multiple times with different content	A named reference is defined multiple times with different content.	Change all but one of the defined names (including all the appearances of this name without text).
Other messages
MediaWiki:Cite error key str invalid (removed)	Internal software error.	These messages should never occur. If you see them in articles, please contact the MediaWiki developers, who may be able to resolve the situation. (These error messages have been removed.)
MediaWiki:Cite error stack invalid input (removed)

Technical information

Internal messages are generated by the Cite.php extension and shown as a MediaWiki message. See the Parser hooks section of Special:Version for the installed version of Cite.php. These messages are in the MediaWiki namespace and can be modified only by admins.

Cite.php internal message	MediaWiki message
Cite error	Cite error: $1
Cite error key str invalid (removed)
Cite error ref no input	Invalid <ref> tag; refs with no name must have content
Cite error ref no key	The opening <ref> tag is malformed or has a bad name
Cite error ref numeric key	Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title
Cite error ref too many keys	Invalid parameter in <ref> tag
Cite error references invalid input (removed)
Cite error references invalid parameters	Invalid parameter in <references> tag
Cite error references invalid parameters group (removed)
Cite error references no backlink label	Ran out of custom backlink labels. Define more in the MediaWiki:Cite references link many format backlink labels message.
Cite references link many format backlink labels	This is a list of the backlink labels used in the reference list, currently from a to zz
Cite error references no text	Invalid <ref> tag; no text was provided for refs named $1
Cite error included ref	Closing </ref> missing for <ref> tag
Cite error stack invalid input (removed)
Cite error refs without references (removed)
Cite error group refs without references	<ref> tags exist for a group named "$1", but no corresponding <references group="$1"/> tag was found
Cite error references duplicate key	Invalid <ref> tag; name "$1" defined multiple times with different content

See also

• w:Help:Cite link labels