For a definition of ModellingRules, see 6.4.4.4. Other parts of this series of standards may define additional ModellingRules. ModellingRules are an extendable concept in OPC UA; therefore, vendors may define their own ModellingRules.

Note that the ModellingRules defined in this standard do not define how to deal with NonHierarchical References between InstanceDeclarations, i.e. it is Server-specific if those References exist in an instance hierarchy or not. Other ModellingRules may define behaviour for NonHierarchical References between InstanceDeclaration as well.

ModellingRules are represented in the AddressSpace as Objects of the ObjectType ModellingRuleType. There are some Properties defining common semantic of ModellingRules. This edition of this standard only specifies one Property for ModellingRules. Future editions may define additional Properties for ModellingRules. OPC 10000-5 specifies the representation of the ModellingRule Objects, their Properties and their type in the AddressSpace.

Subclause 6.4.4.3 defines how the ModellingRule may be changed when instantiating InstanceDeclarations with respect to the Properties. Subclause 6.4.4.2 defines how the ModellingRule may be changed when overriding InstanceDeclarations in subtypes with respect to the Properties.