Wikipedia:Citation needed

To ensure that all Wikipedia content is verifiable, anyone may question an uncited claim by inserting a {{citation needed}} tag.

Example: Most people believe in ghosts.^{[citation needed]}

Exercise caution before relying upon unsourced claims.
If you can provide a reliable source for the claim, please be bold and replace the "Citation needed" template with enough information to locate the source. You may leave the copyediting to someone else, or learn more about citing sources on Wikipedia.
If someone tagged your contributions with "Citation needed" and you disagree, discuss the matter on the article's discussion page.
Controversial, poorly-sourced claims in biographies of living people should be deleted immediately.

See also