Message numbers ARC9000 through ARC9299 have been set aside for use by DFSMShsm installation-wide exits, either as samples supplied by DFSMShsm or messages written by customers. For an explanation of these messages, customers have to locate the issuing exit or any user-created information for that exit. Message numbers ARC9000I through ARC9099I are intended for installation messages pertaining to RECALL commands. Message numbers ARC9100I through ARC9199I are intended for installation messages pertaining to RECOVER commands.