These lists, which are maintained by your installation, allow users to issue authorized commands and programs, and restrict users from executing certain commands in background jobs.

You can use IKJTBLS in an unauthorized program to determine whether a particular command or program is authorized. Based on whether the command or program is authorized, your program can determine if the command or program must be invoked through the TSO/E Service Facility (IKJEFTSR). Usually only authorized programs can invoke an authorized command or program. However, the TSO/E Service Facility allows any program to invoke an authorized command or program. The TSO/E Service Facility is described in Using the TSO/E Service Facility IKJEFTSR.