This specification provides the possibility to indicate changes in the AddressSpace to a client. Most often this concept is used in list representations, to add or delete Nodes from the list. OPC 10000-3 defines the property 0:NodeVersion and the 0:GeneralModelChangeEventType to indicate such changes. Whenever the address space in this specification is changing, the 0:NodeVersion and the 0:GeneralModelChangeEvent shall be used in the way defined in OPC 10000-3.

As content for the 0:NodeVersion property, a timestamp of the moment the node structure was changed converted to a string with the format yyyy-MM-ddTHH:mm:ss.sZ (using UTC time for display) shall be used.