That’s even better! Would the communities tag themselves in that case?

Maybe an option would be to have a virtual “parent” community, or a community group that communities can join. For example, the supercommunity “memes” could contain meme communities on different instances, aggregating posts and comments when queried. Posting would only be possible to a given community though.

This brings an issue with moderation however. If a participating community would be taken over and used to post spam, there would be no clear mechanism to exclude that community from the parent community. Perhaps it would be better if these parent communities where user curated, so the creator would add one or more communities to the parent, allowing other users to subscribe/unsubscribe from the parent at will.

Ah, that wasn’t there last I checked! I’m so glad the Fediverse is growing so quickly!

Not all of them. I might try setting up a fountain pen community some time soon!