The following special pages appear to be missing help links. This is not an exhaustive list. The suggested target for each is also given. I'll leave this for a few days for any feedback about the targets before uploading patches.
- Extension:Gadgets (2)
Special:GadgetUsage, Special:Gadgets -> Extension:Gadgets (on mediawiki, no dedicated help page exists)
- Extension:Nuke (1}
Special:Nuke -> Help:Extension:Nuke (on mediawiki)
- Extension:StructuredDiscussions (1)
Special:StructuredDiscussions -> Help:Structured_Disicussions (on mediawiki)
- Extension:OAuth (4)
Special:OAuthListConsumers, Special:OAuthManageMyGrants, Special:OAuthManageConsumers, Special:OAuthConsumerRegistration -> Help:OAuth (on mediawiki)
- Extension:CategoryTree (1)
Special:CategoryTree -> Extension:CategoryTree (on mediawiki, no dedicated help page exists)