I surprised that this game use IRC as a chat backbone yet it fails to use main IRC feature, which is creation of your own chanells, i don't see reason why is that. Non standard used #spectator and #multiplayer can be blocked from manual creation, unofficial channels don't need to be listed there for official once are still have there spotlight and and be modded properly, there still some range of permission levels that can be created no to mention they don't need to exposed (like sysop is usually not). IRC supports password channels (k mode), also invite based private channels (i mode). Team chats kind of solve some of problem, but still i got feeling that IRC is not really utilized properly in osu.