I can't seem to find any information on this online
I have a few use cases for supporting some ISO 639-2/3 (3 letter) language codes in pages (less well known language variants)
According to all the documentation I can find, hreflang tags only support ISO 639-1 (2 letter) language codes. That is fine if so, I guess standards take time...
But how could I organise my meta tags to indicate that it is the same page, but in a 3 letter language code?