If there is a need from a z/OS® UNIX environment to invoke an MVS™ program that is link-edited AC=1 and in an APF-authorized library, a sticky bit file or external link can be set up to point to this program. Ensure that the sticky bit file is installed with an owning UID of 0 or with the APF extended attribute, or that the external link is installed with an owning UID of 0. Because a file system mounted as NOSECURITY is considered untrusted, any file or link that is installed in a file system that is mounted as NOSECURITY is not considered trusted for this type of invocation. Also, a file with the APF extended attribute is not honored if found in a file system that is mounted as NOSETUID. Not following this setup will cause the execution of the program to fail when invoked via the z/OS UNIX spawn, exec or attach_exec callable service.