Rhys writes:
Harald, it may be worth saying in your draft that languages codes are of
arbitrary length (up to some suitably large maximum) and will change over
time, so should not be hard-wired into a program, but appear in secondary
configuration files instead. Or some such weasel wording.
I suggested a maximum of 8 letters for langauge and 8 letters
for variant. This is because I think also the IANA-registered
and the private extensions should be short _codes_. There is no
need for potentially long programming language-like identifiers.
The Content-Langauge: field will anyway not be adequate for the
needs of language specialists, as John Klensin has pointed out.
/Olle