HP OpenVMS Guide to System Security: OpenVMS Version 8.4 > Appendix A Assigning Privileges
The VOLPRO privilege permits control only over volumes that the user's process can mount or initialize. Volumes mounted with the /SYSTEM qualifier are safe from a process with the VOLPRO privilege as long as the process does not also have the SYSNAM privilege.
Exercise extreme caution when granting the VOLPRO privilege. If unqualified users can override volume protection, the operating system and service to others can be disrupted. Such disruptions can include destruction of the database and exposure of confidential information.