Some extension hooks are documented under Manual:Hooks/, but I believe it pollutes this area since it's mainly for documentation of core hooks. Any objection for me to move hooks under a place like Extension:{ExtensionName}/Hooks/{HookName}? It would use Template:ExtensionHook, so hooks would still be able to found under Category:Extension hooks.
Topic on Project:Village Pump
That sounds like a good idea. Anything better than having two different approaches.
Either way, this should be formalized on Best practices for extensions#Documentation; something along the lines of:
* MUST: Document available hooks under Extension:ExtensionName/Hooks/HookName (if any)
Sounds good as well, I'll add that bullet point on the page. Recently just added Template:Undocumented Extension Hook so as not to pollute Category:Undocumented MediaWiki hooks as well (they now go under Category:Undocumented Extension hooks)
Good idea!
Fixed Template:Extension/HookProvided and Template:HookUsage for this topic
Thank you for fixing!