If the BPX.SERVER (or BPX.DAEMON) FACILITY class is defined, your system has z/OS UNIX-level security. In this case, the system is more secure than a traditional UNIX system.

This level of security is for customers with very strict security requirements who need superusers to maintain the file system but who do not want these users to have the authority to change their identities to access existing MVS™ resources. To accomplish this, take the additional steps described in Defining servers to use thread-level security.