If a START command (without TERMID) is function shipped or is executed from a transaction-routed transaction, the command can be subject to link security. If link security is in effect, CICS also performs a surrogate user check to verify that the userid for link security is authorized as a surrogate user to the userid for the started transaction. The surrogate check is done at this stage even if the USERID is omitted (if the started-userid is different from the link userid). For more information see Intercommunication link security.