3.2.4.1.18 wsmb:PolymorphismMode
A common way to extend CIM classes is to define derivatives of the CIM class. When a client requests objects of the type for CIM_Process, it is possible to return instances that are actually of a derived type, such as Vendor_Process. The WS-Management CIM Binding Specification defines details for handling polymorphism in the resultSet, as specified in [DMTF-DSP0227] section 9.3.
The Web Services Management Protocol Extensions for Windows Vista clients SHOULD NOT send the PolymorphismMode element.