Re: [APTLD iname 24] Re: [idn] Proposed suggestions from Asia Pacific Top LevelDomain meeting

[Harald Tveit Alvestrand <Harald@Alvestrand.no>]

At 16:57 03.03.00 -0800, Paul Hoffman / IMC wrote:
>At 08:38 AM 3/4/00 +0800, James Seng wrote:
>>The conclusion of the discussion is that IDN is very complicated in 
>>itself. We
>>should not create more complication for IDN by dealing with non-alphanumeric
>>ASCII too.
>
>The latter sentence doesn't make sense to me. In all three encodings 
>proposed so far (UTF-8, UTF-5, cidnuc), it would take *extra steps* to 
>exclude non-alphanumeric ASCII. Thus you are adding, not reducing, 
>complication with this restriction.
>
>This doesn't mean we necessarily want to allow non-alphanumeric ASCII; we 
>cannot say we are doing so to reduce complication.

The big question is "for what".
Adding @ to legal domain names used in email addresses would be VERY 
disruptive. So would adding : to domain names used in URLs.
Depending on our decisions about normalization, 0xFF1A FULLWIDTH COLON 
might be disruptive to URLs, because it is compatibility-mapped to straight 
COLON.

>There is a meta-requirement that the IDN be as simple to implement as 
>possible. Every non-allowed character or character range fights against 
>that requirement, so we should have as few as possible.

Indeed. OTOH, every *allowed* character or range creates one more piece 
that has to be analyzed for interference with the places where they are 
used. Same argument, opposite direction.

                       Harald



--
Harald Tveit Alvestrand, EDB Maxware, Norway
Harald.Alvestrand@edb.maxware.no