The remainder of 4defines the concepts of the AddressSpace. Clause 5defines the NodeClassesof the AddressSpacerepresenting the AddressSpaceconcepts. Clause 6defines details on the type model for ObjectTypesand VariableTypes. Standard ReferenceTypes, DataTypesand EventTypesare defined in Clauses 7to 9.

The informative Annex Adescribes general considerations on how to use the Address Space Model and the informative Annex Bprovides a UML Model of the Address Space Model. The normative Annex Cdefines a graphical notation for OPC UA data.