"LANG is the normal environment variable for specifying a locale." [from](https://www.gnu.org/software/gettext/manual/html_node/Locale-Environment-Var...)
"GNU gettext gives preference to LANGUAGE over LC_ALL and LANG for the purpose of message handling, but you still need to have LANG (or LC_ALL) set to the primary language; this is required by other parts of the system libraries." [from](https://www.gnu.org/software/gettext/manual/html_node/The-LANGUAGE-variable....)