Nowhere does it actually say what JCL stands for, and it is not Job Control Mode.
Robert Virding

Yeah, that’s right! It took me a while to find out and the docs are pretty confusing:

The shell runs in two modes:
· Normal (possibly restricted) mode, in which commands can be edited and expressions evaluated
· Job Control Mode, JCL, in which jobs can be started, killed, detached, and connected


Thanks for the background, Robert!