All privileges that a process can ever potentially use must be included in the permitted set. Conversely, any privilege that is never to be used should be excluded from the permitted set for that program.
When a process is started, that process inherits the permitted privilege set from the parent process. Typically at login or from a new profile shell, all privileges are included in the initial set of permitted privileges. The privileges in this set are specified by the administrator. Each child process can remove privileges from the permitted set, but the child cannot add other privileges to the permitted set. As a security precaution, you should remove those privileges from the permitted set that the program never uses. In this way, a program can be protected from using an incorrectly assigned or inherited privilege.
Privileges that are removed from the permitted set are automatically removed from the effective set.