Re: Comments on IDNA (was: Re: [idn] Reality Check)

[Keith Moore <moore@cs.utk.edu>]

> It would be extremely helpful if IDNA would make it clear that
> applications can and should do something else than ACE.

Transition issues for existing applications are sufficiently
thorny, and differ enough from one application to another, that
it would be difficult to word an appropriate blanket 
recommendation to use "something else".  Even for new applications,
a blanket recommendation may not be appropriate.

The trend of using UTF-8 in new applications is already 
well-established even without encouragement from IDN; the
fact that IDN names are based on the 10646 character 
repertoire will only serve to further encourage the practice.
It will be natural for many of these applications 
to use the UTF-8 form of IDNs also.  Still, this choice needs
to be made on a per-application basis.  For example, should
IMAP server accept search queries for domains in UTF-8 even
though the stored messages that they're searching have those
domains expressed in DUDE (or whatever)?  We might have a guess
about the answer (and your guess might even agree with mine), 
but this is a question that should be answered by MTA and UA 
implementors (who have a better understanding of the issues,
and who will have to deal with their choices) rather than by 
the IDN WG.
 
Keith