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

Note that the ModellingRulesdefined in this standard do not define how to deal with NonHierarchical Referencesbetween InstanceDeclarations, i.e. it is Server-specific if those Referencesexist in an instance hierarchy or not. Other ModellingRulesmay define behaviour for NonHierarchical Referencesbetween InstanceDeclarationas well.

ModellingRulesare represented in the AddressSpaceas Objectsof the ObjectType ModellingRuleType. There are some Propertiesdefining common semantic of ModellingRules.This edition of this standard only specifies one Propertyfor ModellingRules. Future editions may define additional Propertiesfor ModellingRules. OPC 10000-5specifies the representation of the ModellingRule Objects, their Propertiesand their type in the AddressSpace.

Subclause how the ModellingRulemay be changed when instantiating InstanceDeclarationswith respect to the Properties. Subclause how the ModellingRulemay be changed when overriding InstanceDeclarationsin subtypes with respect to the Properties.