If you do not want to restrict data access, you can use the security(none) attribute. Neither exports list checking nor SAF checking is done. Client users can access z/OS files without a z/OS user ID and without using the mvslogin command. They simply mount the z/OS file systems that they want to access and unmount when they are finished. For z/OS UNIX files, the UNIX permission bits are checked before access is granted to the client user. See Figure 1 and Table 1 for information on permission checking.