That was a major part of the reason I made the suggestion regarding partial pubkey queries. If you can query for a user's 10002 with just the first 6 characters of their pubkey, you can find their outbox relays where the event is likely stored, since 10002 events are intended to be shared far and wide.
Discussion
That said, this could indeed be done with a custom relay. One that pulls in 10002 events from all known relays and allows for a query of just the first several characters of a pubkey. There is no need expect all relays to have this behavior. From there the client will have the relays it can expect to find the event, and relays DO currently support partial event ID queries, right nostr:npub1arkn0xxxll4llgy9qxkrncn3vc4l69s0dz8ef3zadykcwe7ax3dqrrh43w?
Not all relay implementations support partial id queries
I think it would be worthwhile to PR existing relay implementations. But if that fails, a custom relay implementation expressly for this purpose would be a great idea
I didn't mean custom implementation for this purpose, I think you can probably do better with a custom relay implementation.
I mean, if it's already custom you can assign a serial number to each event and map those numbers to real events in a custom database. Then convert those numbers into single or double-word mnemonics for users.
Or is that boring, doesn't contain cryptographic tricks, centralized? Maybe it is, but I think boring is good and centralized is fine as long as it plugs into the rest of the Nostr ecosystem.
Nothing else I know of can do this at a protocol level. It's like a compression cheat code. I think we should take advantage of it