Re: [EAI] Thinking about requirements / downgrade

[Shawn Steele <Shawn.Steele at microsoft.com>]

> IDNA made the leap of faith that no existing application would be
> inconvenienced if we assumed that no domain name label starting "xn--"
> existed with any other use than IDNA.

> What assumption can we make?

It seems unlikely that mailboxes start with xn--, though other values could maybe be used.  Should such an address already be used, I suggest that it is esoteric enough that such existing usage shouldn't penalize the rest of the Internet moving forward.  Additionally, it'll probably still "work", though some clients might render it funny.

My earlier objections had nothing to do with "does a mailbox looking like that already happen to exist", but rather:
* Punycode is NOT human-friendly.
* UTF-8 on the wire is much cleaner.

My shift in thinking is that UTF-8 on the wire is still strongly preferred, and that a human-friendly address is also required.

-Shawn