Re: prefer-language tag

["John D. Burger" <john@mitre.org>]

Mark Crispin wrote:

> Here's what I think the behavior should be:
> 1) If the user requests a "generic" form of the language, it will match either
>    a server's "generic" form or a dialect of the server's choosing.
> 2) If the user requests a specific dialect of the language, it will match
>    either that dialect on the server or a generic form offered by the server,
>    but *NOT* any other dialect.

As I understand RFC 1766, this is expressively not allowed (Section 2.1):

   There is no guaranteed relationship between languages whose tags
   start out with the same series of subtags; especially, they are NOT
   guraranteed [sic] to be mutually comprehensible, although this will
   sometimes be the case.

   Applications should always treat language tags as a single token; the
   division into main tag and subtags is an administrative mechanism,
   not a navigation aid.

In particular, I suppose there are examples involving Chinese (e.g., ZH,
ZH-TW, and ZH-CN) where the proposed behaviour is problematic.


By the way, I'm not on 
- John Burger
  MITRE