freebsd-dev/sys/miscfs/union
..
libc.fts.c
libc.opendir.c
libc.readdir.c
README
union_subr.c
union_vfsops.c
union_vnops.c
union.h

If you plan on using union mounts, then you should consider replacing
three files in "libc/gen" in the C library with the files in "libc"  
in this directory.  The replacement version of opendir() automatically
removes duplicate names when a union stack is encountered. The other
two files do special handling of whiteouts. You will then need to 
rebuild the C library and all commands.

@(#)README	8.2 (Berkeley) 11/4/94