Help:Footnotes

This page explains how to create Footnotes in articles. In this context, Footnotes are a Wikipedia specific manner of including sources and should not be confused with the general concept of footnotes. This how-to does not cover the formatting of citations.

Footnotes are used most commonly to provide references (bibliographic citations) to reliable sources in articles, explanatory information, and source information for tables and other elements. The use of Footnotes is not required by any policy or guideline, and other systems of inline citation, including and, may be used at the editors' 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 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 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 to reliable sources, 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:
 * Footnote markers show in the content as a superscripted footnote label enclosed in brackets. The footnote label shows as a number, letter or word. The footnote label is linked to the full footnote with a matching label. Examples:  . Clinking on the footnote marker jumps to the footnote and highlights the citation.
 * A Footnote contains the full citation and shows in a list wherever the reference list markup is placed. Footnotes are formatted in an ordered reference list with each entry starting 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
This is 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.

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 saved 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 most anything, but it is recommended that it have a connection to the citation or note. A major practice is to use the author-year or publisher-year for the reference name.

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:

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.

For example:

{{markup|title=30em wide columns Lorem ipsum dolor sit amet.
 * Lorem ipsum.

Footnotes: list-defined references
Footnotes can also be defined within the reference list and invoked in the page content. This keeps all of the citations in one central location. The syntax is:

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.

Previewing edits
When you edit a single section of a page, the footnotes list will not be visible when you preview your edits. Thus you ordinarily cannot see how your footnotes will later appear when you save your edits.

You can insert a into the edited section temporarily and remove it before saving; you will still not be able to see named references which were defined in other sections.

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

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

The syntax for the reference list with a group is:
 * The group name must not be enclosed in quotes.
 * The group name must not be enclosed in quotes.

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

Predefined groups
There are several predefined groups that can have a styled reference list such that the footnote labels match between the footnote marker and the footnote in the reference list. These predefined groups and reference lists have templates that make the markup simpler and also allow a standard reference to be inserted, so that an explanatory note can have a reference.

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

Issues
 * Backlink labels are always styled as lower-alpha. This can be confusing when the efn is used.
 * The entries in the reference list will show the default decimal styling if:
 * The value for group does not exactly match one of the predefined values.
 * The value for group is enclosed by quotes.
 * reflist 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 navbox or one of the variants and the style is set to ; to resolve this, replace the style with.

Reference lists: multiple use
Multiple reference lists may be included on a page. If each reference list uses a different group name, then there are no issues. If columns are set, then there are no issues. Multiple reference lists without group names or columns may be used, but they must be explicitly closed so that the references intended for one list do not appear in another list. To close a reference list, use:



For examples:

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.

Footnotes: embedding references
Explanatory notes may need to be referenced. Due to limitations in the software, reference tags cannot be nested; that is, a set of  tags cannot be placed inside another pair of  tags. Atttempting 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 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.{{#tag:ref|A footnote. |group=nb}}

Footnotes: 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.

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. Another approach is to attach a right after the reference pointer. 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.

Limitations

 * Templates can not be substituted within <ref ></ref> tags. will remain as-is.
 * tags can not be nested. See above for solution.