This file contains all the mount specifications for the file systems mounted on this directory.
The name of the file begins with /etc. Usually, the policy file name matches the directory name. For example, if you specify a directory named /u, you would specify a policy name of /etc/u. If you specify a directory named /nfs/bookserv, you could specify a policy name of /etc/bookserv.map. These two entries in the master file would be:
/u /etc/u.map /nfs/bookserv /etc/bookserv.map