A restriction to level 2, which excludes most combining characters, would
severely restrict the expressive power of ISO 10646, and in consequence the
ability of the protocols that use it (in the UTF-8 form) to represent the
textual content that they need to represent for truly world-wide operation.
IMHO, such a restriction is too serious to be entertained solely on the
basis of "we suspect that level 2 is sufficient." ISO has not found it
sufficient, it has level 3; Unicode has *only* level 3. And I think the
purposes of Internet protocols (at least those that carry text) are the
same as the purposes underlying ISO 10646 and Unicode: to enable
communication in all the world's languages.
>Alternatively, register a new value, say, 'utf-8-level-2'.
There is actually a revision of RFC 2044 underway. The latest draft
(ftp://ds.internic.net/internet-drafts/draft-yergeau-utf8-rev-01.txt) has a
discussion of version-specific labels, which you may find relevant to your
proposal of a level-specific label. Please take a look, and come back with
your proposal -- preferably to the ietf-charset list, as suggested by
Harald -- if you still think it is appropriate.
Regards,
--=20
Fran=E7ois Yergeau <yergeau@alis.com>
Alis Technologies inc., Montr=E9al
T=E9l : +1 (514) 747-2547
Fax : +1 (514) 747-2561