Hi Adi,

CN is Cantonese, while ZH is Mandarin. There probably won't ever be a global replace but if some are mis tagged, we can only rely on the community to fix them.

So it is IS0 639-1 and then some extra? As CN doesn't exists in 639-1: http://en.wikipedia.org/wiki/List_of_ISO_639-1_codes. (Does highlight the fact that 639 was meant for written languages and even then is a bit out dated. Doesn't distinguish between simplified and traditional Chinese. I think the Chinese got screwed on 639-1 :)

I think the Chinese got screwed on 639-1 :)

Haha, they totally did.

With regards to ISO-639 in general, I agree. Choosing it is a 5 year old decision now though and migrating away from it would affect every single API user. It's probably not going to change any time soon.

To be honest, other than rolling your own, your options aren't great. Even when you get down to zh-cn and zh-hk it isn't great.