RACF® can send an ENF signal to listeners in the following situations:

• When a SETROPTS RACLIST command affects in-storage profiles used for authorization checking, RACF sends a type 62 ENF signal to listeners.
• When a CONNECT, REMOVE, ALTUSER REVOKE, DELUSER, or DELGROUP command has affected a user's group connections, RACF sends a type 71 ENF signal to listeners.
• When a PERMIT, RDEFINE, RALTER, or RDELETE command has affected a user’s or group's authorizations to resources, RACF sends a type 79 ENF signal to listeners. This signal is issued only for classes that have been defined in the RACF Class Descriptor Table with the SIGNAL=YES option.

Listeners of these signals should follow the guidelines documented in z/OS MVS Programming: Authorized Assembler Services Guide on coding listener exit routines, particularly:

• Avoid such time-consuming processing as obtaining large amounts of storage through the GETMAIN macro, issuing WAITs or issuing SVCs that issue the WAIT macro, and performing I/O operations.
• Avoid requests for the local lock.
• Avoid using multiple listener user exits.