9c3a3d9f_Basic_CLIST_commands__Its_USE
[S.No] 13 [Clist Command] &SYSAPPCLU [Its USE] 
&SYSAPPCLU contains the MVS/APPC logical unit (LU) name. The LU name identifies the TSO/E address space your CLIST will be running in as the SNA addressable unit for Advanced-Program-to-Program-communication (APPC).
Basic CLIST commands
Its USE