Subject: [idn] A question about the display of decoded IDNs

From: Yves Arrouye <[email-masked]>
Date: Thu, 29 Mar 2001 21:15:02 -0800

Hi,

Pardon me (and please point me to the right place!) if this topic has been
discussed. I searched in the titles of the mailing list archives, but didn't
seem to find a related thread, nor is the IDNRA draft addressing this issue.
 
As I was generating an XHTML document with a bunch of ACE-encoded strings
and their decoded IDNs, I wondered how applications in Asia will be able to
pick the correct glyphs for display of some characters?

My understanding is that a result of the Han unification process in Unicode
is that some characters with culturally different glyphs are shared between
Chinese and Japanese (and Korean?). In HTML and XML, people use a language
attribute to let the rendering software pick the glyphs appropriate to a
given language.

In IDN, I haven't seen such tagging in the ACE encodings I've looked at
(namely RACE and LACE; pardon me if this has been addressed in other ACEs).
As a matter of fact, the ACE is always being said to be applied to a UTF-16
buffer, with no mention of language tagging (wether the name uses a single
language or many). Which means that there may be an upcoming display problem
for IDNs.

Will IDN support the upcoming tag characters U+E0000-U+E007F when Unicode
3.1 will be released? Won't such tagging be costly and make the names even
shorter (a tag would use something like three code points, say U+E0001
LANGUAGE TAG followed by a two-letter language code, e.g. 6 code units, and
force a plane change and back)? If .com still prevails with IDNs, one won't
certainly be able to make (risky) assumptions on the language based on the
TLD of the domain name.

YA
--
My opinions do not necessarily reflect my company's.
The opposite is also true..

---

From: "Adam M. Costello" <[email-masked]>
Date: Fri, 30 Mar 2001 08:46:30 +0000

Yves Arrouye <[email-masked]> wrote:

> I wondered how applications in Asia will be able to pick the correct
> glyphs for display of some characters?

I imagine they will use the font preferences and/or language preferences
set by the user.  So a Chinese user looking at a Japanese domain name
might see Chinese-style glyphs instead of Japanese-style glyphs,
but that's no big deal; the user will still be able to remember the
characters, and type them in later from memory, and tell someone else
over the phone what to type.

> Will IDN support the upcoming tag characters U+E0000-U+E007F when
> Unicode 3.1 will be released?

No.  (I don't mean to speak for everyone, but I think there's consensus
on this point.)  Today's non-internationalized ASCII domain names do not
contain tags specifying typeface, or ligatures, or language, or which
style of lowercase g to use:

    @@@@@ @@    @@@@@@@
   @@   @@     @@    @@
   @@   @@     @@    @@
    @@@@@      @@    @@
   @@           @@@@@@@
   @@@@@@@@          @@
  @@      @@   @@    @@
   @@@@@@@@     @@@@@@

A domain name is not a document, it's an identifier.  It must be
possible not only to look at it, but to type it in, and speak it.
If the identifier for a domain consisted of not just a sequence of
characters, but also the particular style with which each character was
drawn, it would be much harder to remember, speak, and type the domain
name with sufficient precision.

When you write domain names in documents, you can tag them to your
heart's content.  But in mail headers, or in the Location field of a web
browser, it would be way more trouble than it's worth.

AMC