You can pass up to 64-bits of information to the user routine with the EXITPARMS parameter. The contents of this area are user-defined, and might, for instance, be used to pass the address and ALET of a storage area containing information that determines how the exit routine should perform its processing.

• When passed to a message user routine, MEPLUSERPARMS in the message exit parameter list (MEPL) contains this information.
• When passed to a message notify user routine, MNPLEXITPARMS in the message notification parameter list (MNPL) contains this information.