All storage provided by the application on the APPCCMD request must be associated with the ACB task or a task higher in the TCB hierarchy. This includes CSM buffers as well as private area storage that is mapped by the RPL and XBUFLST.

For applications running in cross-memory mode, prior to issuing an HPDT request, the application's primary address space must ensure that CSM storage is associated with the primary ASID and task of the ACB. For an HPDT send, the application can use CSM services to change ownership of the buffers to the ACB task. For an HPDT receive, the application should pass the ACB task identifier to VTAM® on the APC82TSK field in the XBUFLST-receive vector so VTAM can perform the ownership change (VTAM uses the ASID of the primary address).