Providers of dynamic properties implement either the IDynamicPropertyNotify or the IDynamicPropertyNotify2 interface, with the Property Inspector as listener. An implementors fires the OnChanged() event when one of its dynamic properties changes. These interfaces also provide the GetCurrentSelectionSet() method, which returns pointers to the object or objects whose properties are currently being edited. This list is equivalent to the IUnknown array passed as the first argument to the most recent invocation of the IPropertyInspector::Reset() method.
IDynamicPropertyNotify and IDynamicPropertyNotify2 differ only in the value that they pass to the OnChanged() method. IDynamicPropertyNotify objects always pass a pointer to an IDynamicProperty object. IDynamicPropertyNotify2 objects pass an IUnknown pointer, which the Property Inspector may query for either IDynamicProperty or IDynamicProperty2.