Allows a program or operator to designate the user IDs and associated passwords that the local LU uses to verify the identity of a user ID carried on allocation requests it receives, and to designate the remote LUs that are permitted to send to the local LU allocation requests carrying a user ID and either a password or an already-verified indication. Also allows the program allocating a conversation to specify that the allocation request carry the user ID received on the request that started the program, together with an already-verified indication.

VTAM support for this option set is provided by the SECACPT operand on the VTAM APPL statement. RACF support for this option set is provided by the CONVSEC field in the SESSION segment of the RACF APPCLU profile. APPC/MVS support for this option set is provided in its TP attach processing, which uses RACF services to verify the user ID and password on allocation requests it receives. Support for this option set is also provided in the ATBALC2, ATBALLC, and CMALLC communications calls.