HP OpenVMS Guide to System Security: OpenVMS Version 8.4 > Appendix A Assigning Privileges
When the process's group matches the group of the object owner, the GRPPRV privilege gives a process the access rights provided by the object's system protection field. GRPPRV also lets a process change the protection or the ownership of any object whose owner group matches the process's group by using the DCL commands SET SECURITY.
Grant this privilege only to users who function as group managers. If this privilege is given to unqualified users who have no need for it, they can modify group UAF records to values equal to those of the group manager. They can increase resource allocations and grant privileges for which they are authorized.