Typically, the components of an ObjectTypeare fixed and can be extended by subtyping. However, since each Objectof an ObjectTypecan be extended with additional components, this standard allows extending the standard ObjectTypesdefined in this document with additional components. Thereby, it is possible to express the additional information in the type definition that would already be contained in each Object. Some ObjectTypesalready provide entry points for server-specific extensions. However, it is not allowed to restrict the components of the standard ObjectTypesdefined in this standard. An example of extending the ObjectTypesis putting the standard Property NodeVersion defined in OPC 10000-3into the BaseObjectType, stating that each Objectof the Serverwill provide a NodeVersion.