FSS output descriptor support allows a functional subsystem to use JCL that is not known to JES. An FSS can use this JCL to support sophisticated printers. Users can specify complex printing requirements for data sets that are processed by FSS devices.

Data set printing requirements are specified on the OUTPUT JCL statement. This statement supports several FSS-specific parameters such as FORMDEF and PAGEDEF. z/OS MVS JCL Reference describes each of the parameters on the OUTPUT JCL statement.