Help:Footnotes

This page explains how to create footnotes on Wikipedia pages. Footnotes are used most commonly to provide references (bibliographic citations) to reliable sources in articles, although they have other uses as well. They are generated using the following tags in the editable text of a page:  within the text, and or  at the end where the footnote list is to appear.

The most common use of footnotes in Wikipedia articles is to provide inline citations to reliable sources, although footnotes can also be used for other purposes. The use of tags is not required by any policy or guideline, and other systems of inline citation, including parenthetical referencing, may be used at the editors' discretion. However, tags are by far the most popular system for inline citations.

This page concerns technical methods for creating footnotes. Only certain types of material on the English Wikipedia are required to have an inline citation to a reliable source. 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 WP:MINREF (minimum requirements for all articles), the Good article criteria (for Good articles), and When to cite (for Featured articles). For advice on how to organize and format bibliographic citations to reliable sources, see Citing sources and Citation template examples.

Overview
The footnoting system involves two elements:
 * Footnote markers. These are links, usually in the form, etc. Clicking on a footnote marker will take you to the correspondingly numbered footnote.
 * The footnotes themselves. These appear in a list (usually placed near the end of the article), and include links back to the corresponding footnote markers.

Footnote markers are generated using tags. The list of footnotes is generated using the tag, or the corresponding  template, placed in the editable text at the point where the footnotes are to appear. The text of a footnote is placed between opening and closing  tags, either at the point where the footnote marker is to appear, or within the  element. If the page contains footnote markers but no footnote list, a red cite error message will appear.

Creating a footnote marker
At the point in the page text where the footnote marker is to appear, enter the text of the footnote and put the two pieces of coding before and after the footnote-text, like this:


 * LibreOffice For Starters, First Edition, Flexible Minds, Manchester, 2002, p. 18

This will create a footnote marker (automatically numbered). The footnote text itself will appear in the footnote list, generated as described below. If there is no footnote list markup, a red warning message will appear, reminding you to write the markup that generates the list.

You can include formatting and links in a footnote in the usual way, although certain features, such as the pipe trick and template substitution, will not work in footnotes. For the formatting of references, citation templates, such as a generic, or more specific , , etc., are available, although many editors prefer not to use them. See Citing sources for details on how references can be structured.

If a footnote contains a link to an external site, and the link contains some non-displaying characters, it may not display correctly. In particular, a line break (carriage return) embedded in the descriptive text will affect display. This may happen if the description is pasted from a source with line breaks, and is particularly difficult to find if the hard break is inserted where it happens to be at the end of a line on the edit screen. Example: this footnote is formatted correctly. This is formatted identically (with different wording), but has an embedded line break after "page." . These footnotes display as:

To aid readability in the edit window, a single newline can be added after the closing tag before continuing with the text of the paragraph. This has the same effect as putting a space after the closing tag.

Multiple references to the same footnote
It is possible to refer to the same footnote more than once, in other words to generate several footnote markers, all with the same number, which link to the same footnote. To achieve this, named footnotes (named references) are used. The same naming system is also used for list-defined references.

A footnote is named using the name attribute of the tag. Choose a name (such as "Perry"), and then at one of the footnote marker points (it makes sense to choose the first), enter the footnote like this:


 * Perry's Handbook, Sixth Edition, McGraw-Hill Co., 1984

Then you can create another identical marker linking to the same footnote from any other point in the text, by entering the following (note the final slash):



Note that when Shortened footnotes are employed (using sfn to create footnotes under Reflist and efn to create explanatory notes under Notelist) then naming is not required because identical footnote markers are automatically identified and consolidated into a single footnote.

Creating the footnote list
At the point where you want the text of the footnotes to appear, usually at the end of the article in a section titled "References" or "Notes (see the Footers in the layout guideline for more information), put the following markup:



A commonly used alternative, which includes some formatting, is the template:



This template has parameters available for splitting the list into columns, and for controlling their width. For example, puts the list of footnotes into two columns. (For more options, see the reflist template documentation.)

The footnote list must be inserted on the page below (after) all the footnote markers.

If the page has markup to generate a footnote list, but there are no footnote markers on the page, the list will simply appear as a blank line. No warning or error message is displayed.

List-defined references
In order to make the article text easier to read in the edit window, particularly in sections with many citations, editors may decide to write all footnotes in the shorter "named" form. This can be done using the list-defined references function, where the content of the references is defined within the reference list, rather than in the article text. The syntax is as follows:

This can also be done using the template with a refs parameter:

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

What it looks like
When a page with footnotes is displayed in a browser, the tags in the main text are converted to auto-numbered superscripts, like this:

Clicking on a numbered superscript takes you straight to the text of the corresponding footnote. (The item is not a footnote marker; it is produced by the  template, used to indicate a point where a reference ought to be provided.)

The tag or  template is expanded to show the text of the footnotes against their corresponding numbers, like this:

{{quotation| ; to resolve this, replace the style with.

Multiple reference lists
It is possible to include multiple instances of the reference list markup or  on a page. Care must be taken to ensure that multiple reference lists are closed so that the references intended for one list do not appear in another list. To close the reference list markup, simply use any parameter in the reference list markup. Normally different reference lists would use different groups, so the reference list markup will be closed.

In this example, the reference list markup is unclosed and the reference list is repeated in the two subsequent lists and the third in-text footnote number is rendered incorrectly:

To prevent this and close references so that they are not rendered incorrectly, the reference list markup must include any parameter, such as group, refs or a column parameter. If parameters are not desired, a dummy parameter may be used, by convention close. For example:

Embedding references within footnotes
Explanatory notes may need to be referenced. Due to limitations in the software, reference tags cannot be nested—a set of  tags cannot be placed inside another pair of  tags; attempting to do so will result in a cite error.

The magic word #tag:ref may be used to nest references. The markup is:



Where refcontent may include  tags. The name and groupname are optional, but must come after refcontent. If the groupname is not specified, then the main and nested references will be rendered into the same reference list. Attempting to use #tag:ref more than once within list-defined references will result in a cite error.

Example:

{{markup
 * The quick brown fox jumps over the lazy dog.{{#tag:ref|A footnote. |group="nb"}}

Explanatory notes
Most footnotes are citations, which identify sources. Another kind of footnote is an explanatory footnote which is a comment that would be too detailed or too awkward to include in the body of the article. The Wikipedia Manual of style does not mandate a layout for explanatory footnotes at the bottom of the article, and in fact provides for several approaches that are acceptable. An important factor whether or not are used or not. Here are some common approaches to laying out the footnotes.

A
This example uses standard footnotes with all citations and explanatory notes in a single Notes sections:

{{markup
 * The Sun is pretty big. But the Moon is not so big. The Sun is also quite hot.

B
This example uses Shortened footnotes with a References section and combines explanatory notes and citations in a Notes section:

{{markup
 * The Sun is pretty big. But the Moon is not so big. The Sun is also quite hot.

C
This example uses list-defined references mixed with explanatory notes. {{markup
 * The Sun is pretty big. But the Moon is not so big. The Sun is also quite hot.

D
This example uses list-defined references and creates a separate notes section by using group names. {{markup
 * The Sun is pretty big. But the Moon is not so big.  The Sun is also quite hot.

E
This example is similar as the previous one above, except that it allows references embedded within footnotes. {{markup
 * The Sun is pretty big. {{efn|But the Sun is not as large as some other stars. }} But the Moon{{efn|The Moon goes by other names, such as Selena. }} is not so big. {{efn|Historically the Moon was not always considered to be large. }} The Sun is also quite hot.

Citing one book repeatedly with different 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. Another approach is to attach a right after the reference pointer. and replace the "8" with whatever page number.

For example:

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

Limitations

 * Templates can't be substituted within  tags. will remain as-is.
 * tags can't be nested. See above for solution.