The Output DD statement

You can provide print data set descriptors by adding output JCL statements to the dependent region JCL. The application program passes the name of the output JCL statement in the dependent region JCL using a CHNG call with the OUTN parameter. IMS can use the output JCL statement when the print data set is dynamically allocated.

If the output statement does not exist in the dependent region's JCL, dynamic allocation fails when the first insert is done. The application program receives a status code AX indicating the insert (ISRT) failed.