Language codes

Language codes are used to identify a language internally in a computing system, just like Unicode is used to identify letters (slightly simplified). Without a language code, there’s no way to communicate to a spelling checker what language to use for checking, to tell the system which voice to use for voice-over, or how to tell the user which language is currently being used for whatever tool.

There are several standards for language codes, but only one is used in computing systems: the ISO 639 series, by way of the BCP 47 standard. Other language coding systems are thus not considered.

It is unfortunate that the ISO 639 series of language codes are maintained by several entities. It would be desirable that they be all maintained along the same lines as Unicode, with regular updates and corrigenda.