Preface (updated 2020-01-22) JCL (Job Control Language) decks are used to submit JOBs via a reader device or an online edit session for batch processing on the public domain OS, MVS 3.8J (MVS will be used to mean MVS 3.8J in this post). As a MVS 3.8J hobbyist / enthusiast, the previous statement is elementary and unequivocal. The purpose of…