ARTCSKL is the listener of ART for CICS TCP/IP socket and can perform the same functions as CICS TCP/IP listener CSKL. When client request comes, it passes the request to work task for processing, and then waits for another client request. ARTCSKL can run in standard or enhanced mode; you can set the mode through FORMAT parameter of ART for CICS TCP/IP socket listener configuration file (listener.desc).