So lang is whatever was passed in by the consumer, as in "i18n.language = <lang>". Since apps can make this assignment generally, it'd probably be better to have some validation in there anyways.
I'm not entirely sure why it works, I'd have to investigate. When the domain is updated, even if it is unchanged, the UI is re-translated using the value of LANGUAGE it seems.
So lang is whatever was passed in by the consumer, as in "i18n.language = <lang>". Since apps can make this assignment generally, it'd probably be better to have some validation in there anyways.
I'm not entirely sure why it works, I'd have to investigate. When the domain is updated, even if it is unchanged, the UI is re-translated using the value of LANGUAGE it seems.