Harald writes:
I think the main structure of the tagging should now be:
<Language>-<Variant>
where <Language> may be:
- an ISO 639 language code (of whatever version; make a note that
3-letter languages are expected in a later ISO 639 version)
- The single letter "X" for private extensions
- The four-letter string "IANA" for IANA registered extensions
This would effectively destroy the distinction between the
language level and the variant level for IANA-registered and
private extensions, while keeping it for ISO-registered
languages. I can accept this for private language extensions,
but think it would be a pity for IANA-registered languages. One
reason is that a mail-handling program may be able to react
intelligently on the first part of the language code, even if it
doesn't recognize the variant code used.
The <Variant> may be:
- An ISO 3166 2-letter country code
- An IANA-registered variant of 3 or more characters
I assume that "-" isn't among the characters allowed. In that
case we can always accomodate e.g. some future ISO-standardized
three-letter variant codes by a special prefix, say "i-".
(Lowercase letters are preferred for language codes by ISO;
uppercase letters are used for country and currency codes.)
/Olle