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.