Application authorization

An application must be authorized to use the following interfaces for HPDT services:
APPCCMD with OPTCD=XBUFLST
Like all other APPCCMD requests, HPDT requests under SRB control are always considered authorized. Requests under a TCB, however, must specify BRANCH=YES. VTAM® prevents a TCB mode requester that has not identified itself as authorized from using HPDT services.
IVTCSM macroinstructions
All IVTCSM requests must be from an authorized application program.

For more information about authorization, refer to z/OS Communications Server: SNA Programming.