The remainder of 4 defines the concepts of the AddressSpace. Clause 5 defines the NodeClasses of the AddressSpace representing the AddressSpace concepts. Clause 6 defines details on the type model for ObjectTypes and VariableTypes. Standard ReferenceTypes, DataTypes and EventTypes are defined in Clauses 7 to 9.
The informative Annex A describes general considerations on how to use the Address Space Model and the informative Annex B provides a UML Model of the Address Space Model. The normative Annex C defines a graphical notation for OPC UA data.