locale.conf — Configuration file for locale settings
/etc/locale.conf
The /etc/locale.conf file
                configures system-wide locale settings. It is read at
                early-boot by
                systemd(1).
The basic file format of
                locale.conf is a
                newline-separated list of environment-like
                shell-compatible variable assignments. It is possible
                to source the configuration from shell scripts,
                however, beyond mere variable assignments no shell
                features are supported, allowing applications to read
                the file without implementing a shell compatible
                execution engine.
Note that the kernel command line options
                locale.LANG=,
                locale.LANGUAGE=,
                locale.LC_CTYPE=,
                locale.LC_NUMERIC=,
                locale.LC_TIME=,
                locale.LC_COLLATE=,
                locale.LC_MONETARY=,
                locale.LC_MESSAGES=,
                locale.LC_PAPER=,
                locale.LC_NAME=,
                locale.LC_ADDRESS=,
                locale.LC_TELEPHONE=,
                locale.LC_MEASUREMENT=,
                locale.LC_IDENTIFICATION= may be
                used to override the locale settings at boot.
The locale settings configured in
                /etc/locale.conf are system-wide
                and are inherited by every service or user, unless
                overridden or unset by individual programs or
                individual users.
Depending on the operating system other configuration files might be checked for locale configuration as well, however only as fallback.
The following locale settings may be set using
                /etc/locale.conf:
                LANG=,
                LANGUAGE=,
                LC_CTYPE=,
                LC_NUMERIC=,
                LC_TIME=,
                LC_COLLATE=,
                LC_MONETARY=,
                LC_MESSAGES=,
                LC_PAPER=,
                LC_NAME=,
                LC_ADDRESS=,
                LC_TELEPHONE=,
                LC_MEASUREMENT=,
                LC_IDENTIFICATION=. Note that
                LC_ALL may not be configured in
                this file. For details about the meaning and semantics
                of these settings, refer to
                locale(7).