RE: [idn] Comments on IDNA/stringprep/nameprep

[Erik Nordmark <Erik.Nordmark@eng.sun.com>]

> To make that workable, the basic table should be very restrictive
> and not allow any punctuation or symbols (other than full stops,
> and hyphen-like characters).  The latter can then be taken into
> use as either syntax around domain names or be included in
> certain other kinds of domain names than hostnames on a per
> punctation/symbol basis.

I understand that alternative.

> Going the other way around (as seems to be suggested by the
> authors), frezes at time of first deployment which
> punctuation/symbols can and cannot be used in future
> syntaxes that embed domain names.  In particular, the current
> suggestion *forbids* as special use (i.e. surrounding syntax or
> use in special purpose (non-host) domain names) any non-ASCII
> symbol/punctuation.

I don't understand this issue - stringprep is likely to be used for
many things that use Unicode and need ways to test for equality etc
and not all of these are domain names.
I think (but would gladly accept to be corrected) that the IPS use of
stringprep is intended to be for names of storage volumes (or something
like that).
Given that this intent exists your concern about freezing the set
of punctuation can't possibly be something that the people working
on non-host/domain name use of stringprep see as a problem.

> Even though e.g. [gg] and [g][g] (there are a few hundred other examples)
> are not canonically or compatibility equivalent, they still represent
> the same sequence of Hangul letters, and thus "mean" the same.

Yes, same argument is used for SC/TC needing to be addressed in IDN.

> Even though not all systems display the decompostions correctly yet,
> there is no reason to believe that that they will not be supported
> by most rendering engines for Hangul.  Unfortunately, the normal
> forms cannot be changed at this time, even though that would have
> been better.  There have been many misconceptions around about,
> e.g., where Hangul syllable break are, which may have lead
> to the current situation.  Once those misconceptions are cleared
> up, you will likely see more comments to the fact that [gg] and [g][g]
> (etc.!) are in fact equivalent from a Hangul perspective.

I still don't see why you think this adjustment/fix to Unicode is in scope
for IDN.

> > > 9. User interfaces that encounter mixed script hostname *parts*
> > > should be recommended to "flag" them (ballon warning, color
> > > differentiate, make blinking, bounce automatic 
> > registratations, ...).
> > 
> > By "*parts*" do you mean labels or something else?
> 
> stringprep: "DNS domain name parts";
> 
> idna: "A label is an individual part of a domain name";
> 
> nameprep: "This document describes how to prepare
> 	internationalized host name parts" (I think that's the
> 	wrong approach, e.g. it should apply to the entire name,
> 	but I'm just quoting for the term here.)

I didn't ask what semantics others assign to "parts" - I asked specifically
what you meant in your use of the term.

  Erik