Language and Country/Region Strings
The locale argument to the setlocale function takes the following form:
locale "lang[_country[.code_page]]"
| ".code_page"
| ""
| NULL
This appendix lists the language strings and country/region strings available to setlocale. All country/region and language codes currently supported by the Win32 NLS API are supported by setlocale. For information on code pages, see Code Pages in Chapter 1.