This is an inline template used to flag inappropriately cited deprecated sources, which are questionable and discouraged from use.
When the template is added to a line of text in an article, the resulting clean-up tag links to Wikipedia:Reliable sources/Perennial sources.
This template categorizes its tagged articles into the maintenance category, Category:All articles with deprecated sources, which is hidden in mainspace articles by a default setting in the user preferences. A logged-in user may view this and all other hidden categories by checking Show hidden categories on the Appearance tab of Preferences.
This template takes a compulsory parameter (which a bot will set if the editor doesn't):
|date=date
—in the format "Month Year" or "YYYY-MM-DD", etc.If there is no doubt at all that the source is deprecated and used inappropriately, you can use a parameter to remove the "?" from the template's output:
|certain=yes
or |certain=y