Help:Footnotes on arvau

Wikipedia / 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.

Footnotes or shortened footnotes 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 . On many pages, is used as a wrapper to style the reference list, but it cannot be used with list-defined references due to incompatibility with Visual Editor. CSS style templates can also be used alongside , for example, (and this does not create Visual Editor compatibility problems). In general, is preferred when the capabilities of are not needed.

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. If you are using the desktop site and have Javascript enabled, then hovering your cursor over a footnote marker (or touching it on touch devices) will 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 or 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 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 template will be explained in the next section; can also be used.

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.

Where to place ref tags

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:

Formatting ref tags

The content of the ref tags can be formatted using most wiki markup 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 or 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.

Notes

Footnotes: using a source more than once

You can cite the same source more than once on a page by using named references, also called named footnotes. Using the example name of "manchester2002", the syntax to define a named footnote is:

is the full "named" reference and used only once.

To invoke the named reference:

is the short version that is used other places in the article.

Note that the colon-followed-by-numeral names, like ":0", are currently generated by default in VisualEditor. They should be improved by replacement, using unique information from the citation, such as author and date of publication. For example, change ":0" to "manchester2002", or even better, an exact date, such as "manchester_12/14/2002". Scientific publications and the Yadkard tool always use unique ref names based on the last name(s) of the author(s) and the full publication date.

The actual name used can be almost anything, but it is recommended that it have information derived from 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:

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

Reference lists: columns

Footnote lists generated by or automatically split into columns if there are 11 or more items. The number of columns adjusts responsively to the width of the display, which can range from mobile phones and tablets to wide-screen "cinema" displays.

The CSS "column-width" property is by default set at 25–30 em depending on the skin. Browsers interpret this as a minimum width suggestion; if there is leftover space that cannot be used by an additional column, columns may render wider. This property can be adjusted with or . only allows three settings, "short", "medium", and "long". For example:

allows this property to be set directly. To accommodate different fonts and zoom settings, this should always be done in em and not pixels. For example, to make narrow columns similar to the "short" setting:

The "short" or "20em" setting is commonly used for shortened footnotes, but not for Citation Style 1. For a shortened footnote example, see .

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 for easier maintenance and avoids cluttering the text. This is purely a source code changethe 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:

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

The references will be numbered, and appear in the output, in the order that they are first referred to in the content, regardless of their order within the list. All references in the reference list must be referenced in the content, otherwise an error message will be shown.

Although the template with parameter also supports list-defined references, its use is deprecated as it is not supported by the VisualEditor.

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:

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

The syntax for the reference list with a group is:

or:

groupname

Example:

Note that the footnote labels in the reference list show only the numbers and not the group name.

When using both names and groups, the syntax is:

For the repeated note:

Example with both names and groups:

Example with both names and groups, using list-defined references:

Footnotes: predefined groups

There are several predefined groups that can have a reference list styled so that the label (a superscripted character within square brackets, e.g., ) of an explanatory note or citation ( 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 (superscript lowercase letters like a b c) 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

supports , which works the same as the parameter in (see, for instance, the 4th and 5th examples below). It also supports , which functions similarly to the parameter of the same name in but accepts only 'lower-alpha', 'upper-alpha', 'lower-roman', 'upper-roman', 'lower-greek', or 'note'. Do not enclose values in quotes.
supports the and parameters, which work the same as the same parameters in , and , which works similarly to the parameter of the same name in . Do not enclose values in quotes.

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

Note: With named references you only need to add the details once. For each use after the first you just need to re-use the reference name. Doing this will not cause the inline superscript to display a custom name.

List-defined footnotes are incompatible with Visual Editor. is a simply a wrapper for , which is a wrapper for . Explanatory footnotes can be used with the raw tag (which is compatible with Visual Editor) by specifying the correct group name, for example:

can be used to set column widths.

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 in or does not exactly match one of the predefined values; use or variant as will not be needed.
The value for in or is enclosed by quotes; use or variant as 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 bodyclass=hlist; to resolve this, replace the style with listclass=hlist.
If the note text contains an "=" sign, precede the note text with , like this:
If is embedded within an infobox, a navbox or a reference section that already uses a small font size, the footnotes will likely render in a font size that breaches the 85% minimum needed to maintain accessibility described at MOS:SMALLFONT tags that increase the font size of the output produced by the notelist template. For instance, to call notelist within an infobox that calls , will cause the output of the notelist template to render in the same font size as the remainder of the text in the infobox.

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 templates , and can be used to nest references. The markup is:

or
or
(shorter)

name and group being optional parameters. The content may include tags or another template.

Parsoid also allows using these templates inside ; however, the legacy parser does not render these correctly.

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

Examples:

Using efn

Using refn

With no separate section for explanatory notes. The citation footnotes precede the explanatory footnotes in the list.

Using r

The use of the magic word #tag:ref is valid, but the sequence of parameters is invariant and nonintuitive. as well as and its variants use this markup internally.

{{#tag:ref|refcontent|group=groupname|name=name}}

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:

Talk pages

On talk pages, the template can be used to add a reference list to a specific discussion.

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. The long citation to support the shortened citations can either be placed as a bullet point in a separate References section after the Footnotes section; or it can be placed in the first footnote to cite the source (with the initial relevant page number[s]). The remaining footnotes will use shortened citations (these usually contain the author's last name, the date of publication, and the relevant page number[s]).

A less common approach is to attach a right after the footnote marker replacing the "page" with the appropriate page number or numbers. For example:

compactly combines the functions of and : is equivalent to and is equivalent to .

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 whose definition is outside the section you are editing.

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.

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.