A variant is an optional extension to a locale. It identifies a custom locale that is not possible to create with just language and country codes. Variants can be used by anyone to add additional context for identifying a locale. The locale en_US represents English (United States), but en_US_CA represents even more information and might identify a locale for English (California, U.S.A). Operating system or software vendors can use these variants to create more descriptive locales for their specific environments.