Subject: Re: [EAI] Unicode vs. UTF-8 / Encoding vs. Representation

From: Shawn Steele <[email-masked]>
Date: Tue, 28 Dec 2010 05:02:20 +0000

FWIW: I'm happy clarifying UTF-8 encoding vs Unicode character repertoire.  I missed whatever the problem is with "ASCII vs UTF-8"?  I don't like "ASCII vs non-ASCII" as it would imply other encodings might be valid, and a big goal of the WG is to deprecate other encodings for EAI to alleviate the confusion/problems around encodings.

In the discussion there was some general comments around the "older" existing environment.  IMO EAI requires updates to understand the addresses, so I'm not terribly worried about providing support for things that can be handled by requiring the use of UTF-8 throughout.  EAI senders and receivers would have to understand that stuff anyway.

-Shawn

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http://blogs.msdn.com/shawnste

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From: John C Klensin <[email-masked]>
Date: Tue, 28 Dec 2010 22:40:43 -0500

--On Tuesday, December 28, 2010 5:02 AM +0000 Shawn Steele
<[email-masked]> wrote:

> FWIW: I'm happy clarifying UTF-8 encoding vs Unicode character
> repertoire.  I missed whatever the problem is with "ASCII vs
> UTF-8"?  I don't like "ASCII vs non-ASCII" as it would imply
> other encodings might be valid, and a big goal of the WG is to
> deprecate other encodings for EAI to alleviate the
> confusion/problems around encodings.

Yes, that is exactly the problem with "non-ASCII".  To be
strictly correct, we would need to say something like "the ASCII
subset of UTF-8" (or "Unicode", as appropriate from context) and
"the non-ASCII subset of UTF-8" (ditto), but that is getting
quite cumbersome.

> In the discussion there was some general comments around the
> "older" existing environment.  IMO EAI requires updates to
> understand the addresses, so I'm not terribly worried about
> providing support for things that can be handled by requiring
> the use of UTF-8 throughout.  EAI senders and receivers would
> have to understand that stuff anyway.

Yes, as long as the server can tell it is really [Unicode
encoded in] UTF-8 (and able to return [Unicode encoded in]
UTF-8, rather than actually dealing with a legacy client.  That
is where the VRFY/EXPN discussion and the MAIL parameter one
become important.

    john