in library/scripts/string_pack_config.py [0:0]
def is_valid_language_qualifier(resource_qualifier):
if len(resource_qualifier) == 2:
# language only, e.g.: en
return True
if len(resource_qualifier) == 6 and resource_qualifier[2:4] == "-r":
# language with region. e.g.: fr-rCA
return True
if resource_qualifier.startswith("b+") and "-" not in resource_qualifier:
# special language: e.g.: b+es+419
return True
return False