SYSPROC is a system file that originally contained only CLISTs written for applications or for an individual's use. SYSPROC now can also contain execs as long as the execs are distinguishable from CLISTs.

The SYSEXEC file is searched first, followed by SYSPROC. If your installation uses a large number of CLISTs that are in data sets allocated to SYSPROC and you do not have a large number of REXX execs, you may want to use SYSPROC only and not use SYSEXEC. To use SYSPROC only, a system programmer can change the search order on an installation-wide basis, or an individual can change the search order using the EXECUTIL SEARCHDD(NO) command. You can issue the EXECUTIL SEARCHDD(NO) command directly from the terminal, from an exec or CLIST, and from the JCL input stream run in TSO/E background. The ALTLIB command can also affect search order. For general information about ALTLIB, see Specifying Alternate Libraries with the ALTLIB Command. For more information about the EXECUTIL and ALTLIB commands, see z/OS TSO/E Command Reference.