To facilitate REXX/CICS system and user environment tailoring, REXX/CICS attempts to execute CICSTART, CICSPROF, and user PROFILE execs, if they exist. CICSTART is the system profile exec (STARTUP profile) and it is issued before the first user exec is run after CICS system restart. CICSPROF is the system user profile exec and it is issued when a user enters REXX/CICS for the first time since the CICS system restart. CICSPROF also invokes the user PROFILE.