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. This is a hidden category. It is not shown on its member pages, unless the corresponding user preference (Appearance → Show hidden categories) is set.

This is a tracking category for all set index articles. Pages are put in this category by templates such as ((SIA)), ((mountainindex)) and ((shipindex)). That is, templates built with the ((dmbox)) meta-template, which does the actual categorization. Note that since 2017^[update], ((given name)), ((surname)), and ((nickname)) have also put pages in this category even though such articles resemble disambiguation pages. (See the discussion that brought this about.) Also see Category:All disambiguation pages and Category:All article disambiguation pages for the corresponding lists for disambiguation pages.