The internal reader facility can be used to assign the user portion of the job correlator:

• The job correlator (JOBCORR parameter) can be used to limit the volume of processing that is required to control all batch jobs, STCs and TSUs.
• The job correlator value consists of a system portion and a user portion.
• The user portion of a job correlator can be set by assigning a value to the SYS_CORR_USRDATA symbol before submitting the job through the internal reader. Refer to JES system symbols for details on using the SYS_CORR_USRDATA symbol. The user portion can also be set using the UJOBCORR parameter (see z/OS MVS JCL Reference) or using JES2 installation exits 2 and 52 for JOB JCL statement scan, and exits 20 and 50 for end of job input (see z/OS JES2 Installation Exits).