Posted by andy inman on January 13, 2010 at 8:01pm
Can anyone please confirm whether in all cases (all languages) Drupal will use yy as the url language prefix when the RFC language code is xx-yy. Hope the question makes sense! Background info here. Thanks.

Comments
Forget that :)
It's now been clarified to me - it's a configurable value, not the default. Thanks for listening :)
Currently part of the team at https://lastcallmedia.com in a senior Drupal specialist role.