RFC3066bis: looking ahead

jcowan at reutershealth.com jcowan at reutershealth.com
Tue Jan 20 20:02:10 CET 2004

Addison Phillips [wM] scripsit:

> ?? But the problem would still be: how do you distinguish an ISO3166-2 from
> an ISO639-3?

Just to get the terminology straight, you are talking about 3-letter alphas
from ISO 3166-1.  ISO 3166-2 is used for parts of countries, and most of it
is not freely available.  AFAIK, nobody has proposed using this, except for
a few sign-language tags where it's relevant.

> The lang subtag isn't at issue here, as it isn't the lang code
> that's the problem. It's the secondary tag. If ISO639-3 can identify a
> language exactly, then it can appear in the first position. 

It *can* identify languages exactly.  The difficulty is in providing backward
compatibility with systems that don't understand 639-3.  Let us suppose that
the 639-3 code for Cantonese will be yue.  Then the tags "yue" and "zh-yue"
would mean the same thing, but the first would be meaningless to systems that
don't recognize it, whereas the second would at least be recognizable as
a possible variety of "zh".

All that's needed to allow both yue and zh-yue is to rule out 3-letter alphas
from 3166-1, which are currently required only where a 2-letter alpha is
ambiguous over time.  Using forms like "CS1" solves this problem.

John Cowan   <jcowan at reutershealth.com>   http://www.ccil.org/~cowan
"One time I called in to the central system and started working on a big
thick 'sed' and 'awk' heavy duty data bashing script.  One of the geologists
came by, looked over my shoulder and said 'Oh, that happens to me too.
Try hanging up and phoning in again.'"  --Beverly Erlebacher

More information about the Ietf-languages mailing list