I was thinking about this the other day when trying to design email on nostr. I was trying to model a relay as a mailing list, then you would need some syntax for ccing your message to a specific relay.

We have nprofile or nip05+relays for @ing a specific person and their origin relays, but not if I want to cc a message to a relay which may hold one or more mailing lists 🤔

This would start moving us to a much more decentralized model, at least in the email case, but now I'm thinking how these ideas work in the social case