Table of Contents
<qual> : Alternate format libraries (optional)/usr is the second major section of the
filesystem. /usr is shareable, read-only data.
That means that /usr should be shareable between
various FHS-compliant hosts and must not be written to. Any
information that is host-specific or varies with time is stored
elsewhere.
Large software packages must not use a direct subdirectory under
the /usr hierarchy.