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

[Harald Tveit Alvestrand <Harald@xxxxxxxxxxxxx>]

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@xxxxxxxxxxxxxx