In most cases, English/United States is the default Locale in effect.
A Locale can include up to three arguments. If locale is used at all, it must minimally specify a Language. If Country is used, a Language must also be specified, in the order shown above. The same rules apply if a variant is used.
The Language argument is a valid ISO Language Code. Default is en (English). These codes are the lower-case, two-letter codes as defined by ISO-639. You can find a full list of these codes at a number of sites, such as:
The Country argument is a valid ISO Country Code. Default is “US” (United States). These codes are the upper-case, two-letter codes as defined by ISO-3166. You can find a full list of these codes at a number of sites, such as:
The variant argument is a vendor or browser-specific code. Default is POSIX (Linux/Unix). For example, use POSIX for POSIX, MAX for Macintosh and WIN for Windows.
- English language, no country: “en”
- Portuguese language, Brazil: “pt_BR”
- English language, United States, POSIX Variant: “en_US_POSIX”