Restrictions

Exit 60 runs in the JES2CI address space and cannot access any JES2 private address space data areas, such as the HCT.
Do not attempt to modify checkpointed data from this exit.
See JES2 exit usage limitations for a listing of specific instances when this exit will be invoked or not invoked.
Exit 60 must be MVS™ reentrant. See “Reentrant Code Considerations” in "Writing an exit routine" for more information.
Do not alter any fields in the $JQE. The changes will not be successful because you are in the subtask environment.
Do not attempt to control the processing of the MVS converter by changing the C/I text at Exit 60. The converter does not examine the C/I text returned from the exit to determine what changes have been made. For example, you cannot use this exit to execute a procedure other than the one initially named on the EXEC statement, nor can you use this exit to control the printing of JCL statement images by altering the MSGLEVEL parameter on the JOB statement.