Why can't I re-add my HZSPRMxx parmlib defined check after I delete it? More understanding of the delete processing...

Here is a possible common mistake: Lets say that you defined a System REXX check in the HZSPRMxx parmlib member using the F hzsproc,ADD | ADDREPLACE,CHECK command. Then, you deleted it using the DELETE command. But now you want to bring it back again, so you issue the ADD,CHECK command. But the command fails, with a message telling you the check already exists, even though it will not appear in SDSF or display output. That is because you deleted the check, but the check definition is still lurking there in the HZSPRMxx parmlib member, and is still loaded in the system. What you need to do to get your check to run again is to put an ADDREPLACE,CHECK statement containing the check definition into a parmlib member, and issue the F hzsproc,ADD,PARMLIB,CHECKS. Your check will now be ready to run.