AFAIK the common case is that it's just "whatever is in ICU/CLDR", there is no "standard". And I've seen them renamed many times - OS versions don't always agr

AFAIK the common case is that it's just "whatever is in ICU/CLDR", there is no "standard". And I've seen them renamed many times - OS versions don't always agree with each other, for example, much less different OSes.