The largest job step completion code in the job steps entered in JCL is the JCL completion code. However, if the job execution is interrupted, the JCL completion code takes a special value.
Also you can specify the completion code of the job step executed last as the JCL completion code in the [Options] sheet of the [Define Operating Information] window.
See "14.5.2 Job Step Completion Code" for details on the completion code when an executing job is interrupted.
