Note that subpages can also be a single capitalized word--this may help with natural naming.
When one wants to add discussion to a page in DocumentMode?, one could add a See Also: /Discuss line. If the discussion becomes long, one might summarize briefly in the main page. Really long discussions might have /MoreDiscussion?.
Subpages could just add "Discuss" to their name if they aren't ready to become top-level pages. Something like /RecentChangesDiscuss? (if /RecentChanges became quite full)