Paul G wrote <snip> I fear "unpredictable" is too often the writers' excuse when they don't know the answer to a request for clarification and can't find out. </snip>
I don't think you will find that that is true in z/OS books. Writers do not make up usage of that word. They are asked to do so because the developers have told them that it is the situation. It might be that "style guidelines" suggest using "unpredictable" rather than something like "not defined". If anything, blame us the design/development folks, not the writers. It is not worth the cost to try to create an exhaustive list of what happens (or could happen) if you were to do something that you're told not to do. It is rarely worth the cost even to create examples of what could happen. It can well be worth the cost to try to create a list of the things that you are allowed to do. As it happens, the offending sentence had already been removed from the 3.1 book. Since the thread started before those books were generally available to be looked at, it's not surprising that that was not realized. If that had not happened, we would have investigated whether there were cases that we could document for which it would be OK to have JCL symbols used to define other JCL symbols. I expect that somewhere the books describe what you get if you use a symbol and that symbol is not yet defined (I do not know exactly where that is). There are probably subtleties about "not yet defined" for cases where you (in effect) "undefine" a symbol (which I think you can do). It might be that the no-substitution-done case is "not defined now", covering both "not yet defined" and also "no longer defined". Peter Relson z/OS Core Technology Design ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
