When the value of a locale environment variable doesn't begin with a slash, the value is interpreted as the name of a locale with the set of currently defined locales:
- The values C and POSIX identify the built-in POSIX locale.
- The value C-TRADITIONAL identifies the built-in locale that's equivalent to the C locale, except that it supports only single-byte characters.
- Any other value identifies a locale with that name within the set of currently defined locales.
7.2. POSIX Locale
The default locale is the POSIX locale.
7.3. Locale Definition
No additional locale categories beyond those specified are supported.
The values of the characters in the portable character set are those defined by the ASCII and ISO/IEC 8859-1 character sets.