I think that these should be in the specifications in order to help with moderation tools in the applications themselves.

I think that at a minimum we should have definitions of how to handle when one server doesn't want to hear anything from another server (so on the sending side what behaviour is required when there is no response, or a connection is refused and on the receiving side this should be allowed)

I am sure that there are other times, like handling specific identities on a server.

It is certainly something I would appreciate on GitHub and something like this is going to need moderation tools of some sort.