RFC3066bis: looking ahead

[jcowan at reutershealth.com]

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
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