Help:Footnotes

This page explains how to create the Footnotes section for Wikipedia articles. In this context, the word "Footnotes" refers to the Wikipedia-specific manner of documenting an article's sources and providing tangential information, and should not be confused with the general concept of footnotes. This how-to does not cover the formatting of citations within the Footnotes section, which is reviewed in Citing sources.

Footnotes are used most commonly to provide:
 * references (bibliographic citations) to reliable sources,
 * explanatory information or
 * source information for tables and other elements.

The use of Footnotes is only one of several options for providing source information in the article. Other systems of inline citation, including and, may be used at the editor's discretion in accordance with the guideline on Variation in citation methods.

Only certain types of material on the English Wikipedia are required to have an inline citation. There is no requirement to provide a citation for every sentence, because multiple sentences may be supported by the same footnote. For advice on which material should be cited, see the guidelines on When you must use inline citations, the Good article criteria and When to cite. For advice on how to organize and format bibliographic citations, see the guideline on Citing sources and examples of Citation templates.

Footnotes are created using the software extension. This extension adds the HTML-like elements , and . The elements are also used in a number of templates; for example, it is becoming more common to use reflist rather than as it can style the reference list.

Overview
The Footnotes system shows two elements on the page:
 * A Footnote marker is displayed in the article's content as a bracketed, superscripted number, letter, or word. Examples shown respectively are: . This footnote label is linked to the full footnote. Clicking on the footnote marker jumps the page down to the footnote and highlights the citation. Hovering over a footnote marker will, depending on the user's settings, show a pop-up box containing the footnote.
 * A Footnote displays the full citation for the source. Together the footnotes are displayed in an ordered list wherever the reference list markup reflist is placed. Each entry begins with the footnote label in plain text. The entire reference list is formatted in a slightly smaller font.


 * Each successive footnote label is automatically incremented. Thus the first footnote marker would be, the second would be and so on. Custom labels are also incremented: ,.
 * For a single use footnote, the label is followed by a caret (^) that is a backlink to the matching footnote marker. For example:


 * If a named footnote is used in the text multiple times, then the footnote has multiple backlinks shown as letters:


 * Clicking on the backlink or pressing backspace returns to the footnote marker.

Footnotes in action
The superscript numeral "1" in square brackets at the end of this sentence is an example of a footnote marker.

Footnotes: the basics
To create the footnote marker, determine the point in the page content where the marker is desired and enter the markup with the citation or note inside the  tags. For example:


 * The reflist template will be explained in the next section.

The content inside the  will show in the reference list. The ref tags can be added anywhere a citation or note is needed. There must be content inside the tags, else an error will show.

Ref tags should follow any punctuation (usually a period), not precede it; see WP:REFPUNC. There should be no space between the punctuation and the tag:

The content of the ref tags can be formatted using most wikimarkup or HTML markup, although techniques such as the pipe trick and template substitution will not work in footnotes. For example:

The ref tag content may also contain an internal or external link:

Reference lists: the basics
Once any number of footnotes have been inserted into the content, the reference list must be generated. For the basic reference list, add reflist wherever the list is desired. Once the page is published and viewed, the footnotes will be automatically generated and numbered and the reference list will be generated. The main reference list is placed in a separate section, usually titled "References", "Notes" or the like.

{{markup
 * This is page content.

Footnotes: using a source more than once
You can cite the same source more than once on a page by using named footnotes. The syntax to define a named footnote is:
 * content

To invoke the named footnote:

The actual name used can be almost anything, but it is recommended that it have a connection to the citation or note. A common practice is to use the author-year or publisher-year for the reference name. This helps editors remember the name, by associating it with the information that is visible to the reader.

Note that the footnote labels are incremented in the order they are used, and that they use the same label when reused, thus the labels can seem out of order:

When using both names and groups, the syntax is:
 * Content

Care should be taken when deleting references to avoid creating a cite error. See Avoiding common mistakes

Reference lists: columns
When using reflist, the list can be split into columns.
 * where xx is the column width in em.

By setting the width in em, the number of columns will automatically be adjusted to the width of the display.

The set columns feature is now deprecated in favor of the option described above, which is better suited to flexible formatting for a variety of display screen sizes, ranging from mobile phones and tablets to wide-screen "cinema" displays. Forcing a fixed number of columns has been disabled in mobile view.

The number of columns to use is up to the editor, but some major practices include:
 * - 1 column (default): Where there are only a few ; see
 * : Where there are many footnotes plus a page-width Bibliography subsection: see
 * : Where are used; see.

For example: Using will create columns with a minimum width of 30 em, {{markup|title=30em wide columns
 * Lorem ipsum.

Lorem ipsum dolor sit amet.

List-defined references
Some or all of the footnotes can also be defined within the reference section/list, and invoked in the page content. This keeps those citations in one central location and avoids cluttering the text (and any infobox). This is purely a source code change – the actual display of the citation in the text to a reader is unaffected. For a more detailed evaluation of this method, see WP:LDRHOW. The syntax is:

or, alternatively,

The footnote markers are included as usual for a named footnote. For example:

{{markup Amazingly few discotheques provide jukeboxes. How razorback-jumping frogs can level six piqued gymnasts.
 * The quick brown fox jumps over the lazy dog.

Footnotes: embedding references
Explanatory notes may need to be referenced. Because of limitations in the software, reference tags cannot be nested; that is, a set of  tags cannot be placed inside another pair of  tags. Attempting to do so will result in a cite error.

The template refn may be used to nest references. The markup is:


 * where name and group are optional. The content may include tags.

The other templates listed below in Predefined groups are variants of refn that include a styled group and have a matching styled reference list template.

Example:

{{markup
 * The quick brown fox jumps over the lazy dog.{{refn|group=nb|A footnote. }}

Footnotes: groups
Sometimes it is useful to group the footnotes into separate lists, for example to separate explanatory notes from references, or to list references for tables, image captions, infoboxes and navboxes. The sequence of footnote labels is independent in each group.

The syntax to define a footnote with a group is:
 * Content</ref>

The footnote marker group name must be enclosed in quotes if the group name includes a space, else a cite error will occur, otherwise quotes are optional.

The syntax for the reference list with a group is:

The reference list group name does not need to be enclosed in quotes.

Example: {{markup
 * This part of the text requires clarification, whereas the entire text is cited. And this needs even more clarification.

Footnotes: predefined groups
There are several predefined groups that can have a reference list styled so that the label (a character within square brackets with all superscripted, e.g., ) of a note or citation (aka footnote, reference) matches and links to the note marker label located in the main text and the label in front of the note's text in the appropriate group's list. There can be more than one of these groups' lists in the Notes, References and other similarly purposed sections.

These predefined note and citation groups have templates that make the wikitext markup simpler. These templates also allow a standard reference to be inserted, so that an explanatory note can have a reference, or citations can be nested.

Note: If the note's text has a reference name that is used more than once, the labels will still match, but the clickable alpha characters that toggle the note's display will be next to the note's label, with links to the multiple locations of its marker in the main text. See WP:REFNAME and the first point below in § Issues.

Template use by reference group type
<section begin=pregrouptable />


 * supports name and group, which work the same as the parameters in . Do not enclose values in quotes.
 * supports the column parameter, refs and group, which work the same as the parameters in . Do not enclose values in quotes.

In these examples, the footnote labels match between the footnote marker and the reference list:

Issues

 * Multiple backlink labels (see WP:REFNAME) are always styled as lower-alpha. This can be confusing when is used. See the note in the introduction of this section, above.
 * The entries in the reference list will show the default decimal styling if:
 * The value for group in or  does not exactly match one of the predefined values; use  or variant as group will not be needed.
 * The value for group in or  is enclosed by quotes; use  or variant as group will not be needed.
 * is indented with the : markup.
 * is used instead of
 * The entries in the reference list will have no styling if:
 * A reference is included in or one of the variants and the style is set to  ; to resolve this, replace the style with.
 * Including external link markup will result in an error. Use the template instead:.

Reference lists: automatically generated
A page with tags but no reference list markup used to display an error, except on talk and user pages. In recent versions of Wikipedia, the error no longer appears; instead an automatically generated reference list (AGRL) is displayed at the bottom of the page.

Compared to the reference lists on properly formatted pages, an AGRL can be confusing to both readers and editors. But it is easily corrected by adding reference list markup such as the following. Add it at the position where the reference list would normally appear. <pre style="width: 10em;">

Footnotes: page numbers
Suppose you would like to cite one book, but different facts appear on different pages. You would like to cite the book again and again, but point each fact to the proper page. Suppose one fact is on page 8, a different fact on page 12, a third fact on page 18, a fourth fact on page 241. You could put a line in the "pages" parameter saying "see pages 8, 12, 18, 241" but a fact-checker might have to check all of them before figuring out the right one. Or, you could duplicate the entire citation for the book in each instance, but that would be redundant. One common approach is to use shortened citations, which requires the use of a References section following the footnotes section. A less common approach is to attach a right after the footnote marker and replace the "8" with the appropriate page number.

For example:

When using list-defined references, can be used for the same style of in-text page references.

Previewing edits
When you edit a single section of a page, the footnotes list will be visible when you preview your edits under the heading "Preview of references", although you will still not be able to see named references that were defined in other sections.

Tools that can be used are the user:js/ajaxPreview or User:Anomie/ajaxpreview.js scripts or the wikEd gadget.

RefToolbar
You can use the citation toolbar to name references. When you first create a reference, you can enter a value in the "Ref name" box. When you want to reuse this reference, click the "Named references" button on the citation toolbar and choose which reference you would like to insert.

Issues and limitations

 * subst: does not work within tags.
 * The pipe trick does not work within tags.
 * The pipe trick does not work within tags.

Flagging inadequate referencing

 * The template should be added to articles where there are some, but insufficient, inline citations to support the material currently in the article. For biographies of living persons, use  instead.
 * The template should be added to articles with no references at all. For biographies of living persons, use  instead.
 * The template is for individual sections that have no citations in articles that have at least one citation somewhere else. For biographies of living persons, use  instead.
 * The template is specifically for articles needing additional medical references.