From: erik(_at_)sra(_dot_)co(_dot_)jp (Erik M. van der Poel)
Subject: ISO 2022
Date: Tue, 04 Jun 91 22:18:53 +0900
While I fully understand your reasoning, I think that it is equally,
if not more, important that the conformance section of any RFC that
talks about 2022, mandate certain character sets. Imagine the
frustration of the poor user who, upon noticing that the RFC mentions
Japanese in 2022, decides to use it, only to find that some supposedly
conformant gateway along the route unilaterally and cheerfully decides
that it is not going to support Japanese just because the RFC author
didn't write a tight conformance section.
And if the RFC is going to clearly specify which subsets, options, etc
(i.e. profile) of 2022 is mandated, there is no compelling reason to
indicate the character sets in the message header. Either you support
the named profile, or you don't conform to the RFC.
I guess I really don't have the same model of how (for example)
10646 is intended to be used. I suspect that everyone will want
their own personal character set to be represented. Specifically
people in Japan will want the Japanese glyphs, people in China
will want Chinese encodings, Taiwan has a different set of encodings,
Korea yet another set, and I haven't even touched on all the ISO8859
variants.
As I read the spec, ISO10646 has many duplicate encodings for the
same screen glyph -- that's why I think of it as a character set registry
framework, rather than a character set itself.
How on earth are you planning on subsetting this problem? It is simply
not acceptible to anyone in country X to say "Sorry, you can't represent
your characters in Mail" -- they will simple go off and do something
ad hoc -- just look at what Europe is doing with 8 bit characters over
SMTP today for a fine example of this principal in action.
If you really think you can specify subsets/common sets/ etc of these
characters, then looking at 10646 is probably a mistake. Instead,
we should pick a single unified character set (such as Unicode) and
then work on specifying how to translate all these national characters
set to and from this unified set.
Neil