In many cases RACF® must copy caller-supplied parameter areas to an area below 16MB, so that the exit can address the parameter areas. However, when the RACROUTE REQUEST=DEFINE exit routines receive the ACCLVL parameter or INSTLN parameters, RACF does not know the format or length of the parameters being passed, and therefore cannot copy the parameters into 24-bit storage. Because the parameter list pointing to these parameters is in 24-bit storage, you must modify the exit routines to handle the parameters if the exit routines access these areas, and if they are passed by callers in 31-bit mode.