Restriction: During ACS testing, only those parameters that are passed to the ACS routines at ACS time are tested. For some data processing, what is specified in the JCL is not necessarily what is passed to the ACS routines. A good example of this is how the RETPD and EXPDT parameters work: if EXPDT is specified in the JCL, during normal processing the RETPD read-only variable is set based on the EXPDT. If your ACS routine logic bases decisions on RETPD variable, and you specify EXPDT as a test parameter, you might get unexpected test results. ACS testing is not designed to simulate all of the possible processing that might occur before ACS processing. You must take care to know what is passed to the ACS routines at ACS time to ensure that you are testing what you expect to occur on your system.