In article <c36e2135-bdc7-7610-0fc2-9071ac8495f1@ix.netcom.com> you write:
I think this is intended to cover what I would call "modern, everyday general use", or the letters that people learn in school, as opposed to arcane, outdated, specialized code points for the same languages and scripts that are also in Unicode for use by scholars and other specialized and expert users.
Seems reasonable. I was hoping we could do something like recommend that mailbox names follow the UTS39 Highly Restrictive profile, with the additional advice that since these are mailboxes and not domain names, if the identifier contains confusable characters that the MTA's mailbox fuzzy match accept all of the confusables as aliases for the name. This would imply that you can't have two mailboxes that differ only in confusables. I don't know if there's "almost confusables" like various accented versions of letters, which I would treat as confusables here and accept as aliases.