If your application defines COM objects that are not database resident, you can extend Properties palette support to them. The Properties palette API provides a new interface, IAcadBaseObject2, and a new template class, IAcadBaseObject2Impl, to support such objects. These APIs provide an alternative to the IAcadBaseObject interface and IAcadBaseObjectImpl class. COM wrappers should derive from IAcadBaseObject2Impl if they wish to support non-database-resident objects. Under no circumstances should a COM wrapper derive from both IAcadBaseObjectImpl and IAcadBaseObject2Impl.