This ReferenceTypecan be used to expose that two different Nodesin the AddressSpacerepresenting the same hardware. It refines the RepresentsSameEntityAs ReferenceTypeand defines that the same entity in the real world shall be a piece of hardware. For example, it can be used to relate an Objectrepresenting a RFID reader based on the AutoID companion specification  with an Objectrepresenting the same RFID reader based on the IO-Link companion specification .
Note: The example given above is special since both specification use OPC UA Part 100 Devices  as base. In this case, the preferred modelling approach is provided in an annex of Part 100, where a composition approach is used.