When the system processes an APPC/MVS transaction program (TP) or a z/OS® UNIX application, this exit allows you to receive control during:

• TP selection processing, which means the TP initiator selected a TP to run.
• TP termination processing, which means the TP initiator completed processing a TP.
• TP change processing, which means the TP initiator was processing a multi-transaction TP. The APPC/MVS transaction initiator or z/OS UNIX BPXAS initiator started another TP as a result of completing another TP.

While JES2 is processing a TP selection request, you could implement Exit 43 to:

• Create installation-specific control blocks to be used by subsequent installation exits that are invoked for the TP after Exit 43.
• Modify the output limits maintained in the $SJB.
• Issue messages to the TP's message log.

While processing a multi-transaction TP, if JES2 is invoked for a change request, you could implement Exit 43 to:

• Reset the output limit counts associated with the TP's SYSOUT data set
• Issue messages to the TP's message log.

During TP termination processing, you could implement Exit 43 to:

• Release any control blocks Exit 43 previously obtained for the TP.
• Issue messages to the TP's message log.