Optional parameters

HLQ: Specifies the name of the high-level-qualifier for the state, control, and journal data sets to which the XSTART command refers. The XSTART HLQ name must be from one to eight characters, and can be any name acceptable to TSO. SYS1 is the default value.
MSGROUTEID: Specifies the user ID to which XRC messages associated with the processing of this command are routed. If the specified user ID is not logged on, TSO saves messages in the TSO BRODCAST data set and displays them after the next logon.
Note: Messages issued by the initial command parser routine are sent to the user ID that issues the TSO command.