The References ReferenceTypeis an abstract ReferenceType; only subtypes of it can be used.

There is no semantic associated with this ReferenceType. This is the base type of all ReferenceTypes. All ReferenceTypesshall be a subtype of this base ReferenceType– either direct or indirect. The main purpose of this ReferenceTypeis allowing simple filter and queries in the corresponding Servicesof OPC 10000-5.

There are no constraints defined for this abstract ReferenceType.