This is a maintenance category, used for maintenance of the Wikipedia project. It is not part of the encyclopedia and contains non-article pages, or groups articles by status rather than subject. Do not include this category in content categories (except for eponymous maintenance categories).

This is a tracking category. It builds and maintains a list of pages primarily for the sake of the list itself. They are not part of the encyclopedia's categorization scheme.

• This category is hidden on its member pages—unless the corresponding user preference (Appearance → Show hidden categories) is set.
• These categories can be used to track, build and organize lists of pages needing "attention en masse" (for example, pages using deprecated syntax), or that may need to be edited at someone's earliest convenience.
• These categories also serve to aggregate members of several lists or sub-categories into a larger, more efficient list (discriminated by classifications).

This is a category to help keep count of the total number of articles with the {{citation needed}} template. They should all be in one of the dated categories, which can be found at Category:Articles with unsourced statements.

With 573,607 articles in this category, it can be hard to choose which one to work on. The Citation Hunt tool makes the task easier by suggesting random articles, which can be sorted by topic-category membership.