First two letters should be the two-letter language code according to ISO 639 Last two letters should be the two-letter ISO 3166-1 alpha-2 country code. The country code and language code should be separated by a hyphen (-)
First two letters should be the two-letter language code according to ISO 639 Last two letters should be the two-letter ISO 3166-1 alpha-2 country code. The country code and language code should be separated by a hyphen (-)