The idea here is to identify the relay with a uri something like thus:

wsn://npub1234....7890@[1001:1003:1003:1004::abcd]:8443

wsn://npub1234....7890@22.33.44.55:8443

wsn://npub1234....7890@centralizeddomainname.com:8443

wsn://npub1234...7890@torelayabcd...efg.onion:8443

Where the format is

wsn://@:

wsn: Web Sockets Nostr

The @ symbol could be changed to something that doesen't have an alternative meaning. Maybe #, %, &, ~ or whatnot

The only downside is it wouldn't play nice with reverse websocket proxies