By default, man searches for a localized manpage in a set of
locale subdirectories of each manpath(1) component.

Locale name is taken from the first of three environment
variables with a nonempty value: LC_ALL, LC_CTYPE, or LANG,
in the specified order.

If the value could not be determined, or is not a valid
locale name, then only non-localized manpage will be looked
up.

Otherwise, man will search in the following subdirectories,
in the order of precedence:

<lang>_<country>.<charset>
<lang>.<charset>
en.<charset>

For example, for ``de_DE.ISO8859-1'' locale, man will search
in the following subdirectories of the /usr/share/man manpath
component:

/usr/share/man/de_DE.ISO8859-1
/usr/share/man/de.ISO8859-1
/usr/share/man/en.ISO8859-1

Finally, if the search of localized manpage fails, it will be
looked up in the default /usr/share/man directory.