There may be one or more variants of the
/lib directory on systems which support more than
one binary format requiring separate libraries.
If one or more of these directories exist, the requirements for
their contents are the same as the normal
directory, except that
This is commonly used for 64-bit or 32-bit support on
systems which support multiple binary formats, but require libraries
of the same name. In this case,
/lib64 might be the library directories, and
/lib a symlink to one of them.
/lib is still permitted: this
allows the case where
/lib are the same (one is a symbolic
link to the other).