Job Control Language (JCL) is a scripting language used on IBM mainframe operating systems to instruct the system on how to run a batch job or start a subsystem. The term "Job Control Language" can also be used generically to refer to all languages which perform these functions, such as Burroughs' WFL and ICL's OCL. This article is specifically about IBM's JCL.
There are actually two IBM JCLs: one for the operating system lineage that begins with DOS/360 and whose latest member is z/VSE; and the other for the lineage from OS/360 to z/OS. They share some basic syntax rules and a few basic concepts, but are otherwise very different.
its a smug fuckers term for people who have now decided to board the gus bus and fill up the amex for next season, not taking into account you may well have supported Brighton for 60 years ,but not pledged you're alleigance to a fans forum until now , hope that helps a bit