Help:Overview of referencing styles

Wikipedia uses various referencing systems to cite sources that support assertions in the article and to add explanatory and supplementary material. This page compares two systems that are currently used (Footnotes and Shortened footnotes) and two older systems that are deprecated and no longer used for new articles (Footnote3 and Parenthetical referencing).

Shortened footnotes
In this short example, note that an in-text cite such as links to the shortened citation in the Notes list, which in turn links to the long citation in the References list:

{{markup The Norwegian blue parrot will not move if its feet are nailed to the perch.{{sfn|Praline|1969|p=12}} Its metabolic processes are a matter of interest only to historians.{{sfn|Praline|1969|p=16}}
 * The brontosaurus is thin at one end.{{sfn|Elk|1972|p=5}} Then it becomes much thicker in the middle.{{sfn|Elk|1972|p=6}}

Footnote3
Footnote3 is a deprecated method of referencing. New articles should not be created with it. Although it appears similar to the Footnotes system, it uses the ref and note templates.

{{markup The Moon, however, is not so big.{{ref|2}}
 * According to scientists, the Sun is pretty big.{{ref|1}}

Parenthetical referencing
Parenthetical referencing is a citation system in which citations are added within sentences using brackets (parentheses). An example would be "Paris is the capital of France (Smith 2020, p. 1)". Full citations are collected in footnotes or endnotes, or in alphabetical order by author's last name, under a "references", "bibliography", or "works cited" heading at the end of the text.

This style of citation was a type of referencing used on Wikipedia until September 2020, when a community discussion reached a consensus to deprecate this format of citation. While some existing articles may still use this form of citation, new articles should not be created with it.