Et is now a macro language
Fragment of a discussion from Support/LiquidThreads
We usually do not change ISO 639-1 related codes. See no/nb. Main reason for this is that Wikimedia does not change FQDNs for their sites.
I don't think there is any immediate need to change this one... the change seems to be brain dead anyway (why not create a new code for the macro language instead?).
Nike