Category:Hooks added in MediaWiki ???

Administrators, please do not delete this category! This is a maintenance category which sometimes contains pages that are in need of attention. If the category is empty then this is a good thing.

The Hooks added in MediaWiki ??? category contains hooks for which the versions to which they apply are (so far) undocumented. If you know when these hooks first were defined, we would be grateful if you would update their documentation page.