Understanding CST WATS_SetOpType for TestStand

If I understand how this Custom Step Type works, it only set 'UUTOperationType' of the selected destination with the value of 'Step.OperationType.OpTypeCodeInt' through the Step Default Expression.

So what is the purpose of others fields in container Step.OperationType ?

What also is the purpose of UUT.UUTOperationTypeDetails ?

Regards,