The reason for "not" that comes to my mind is: * if you are authorized and could run in "someone else's" (unauthorized) address space, your usage of subpool 0 is almost always going to be a system integrity error. And not limited to subpool 0. It would apply also of ANY low private subpool: 0-127 (and 131-132 depending on the key)
There is nothing wrong with an unauthorized application using any of the low privae subpools. After all, they can't use anything else. Peter Relson z/OS Core Technology Design
