When defining an ObjectType, it needs to be considered if there is already an appropriate ObjectType it can derive from. That includes the defined semantic of the ObjectType as well as the defined substructure. The ObjectType may contain an optional substructure that is not needed but should not have any mandatory substructure that is not wanted / needed. Not only ObjectTypes of the base specification should be considered, but also ObjectTypes defined in existing Companion Specifications. The OPC Foundation provides an online search on all specifications (https://reference.opcfoundation.org/). When there is no more appropriate ObjectType defined, the BaseObjectType shall be used as base (as defined in the OPC UA Specification).