This standard Object Node is the browse entry point for ObjectType Nodes. Figure 4 illustrates the structure beneath this Node showing some of the standard ObjectTypes defined in Clause 6. Only Organizes References are used to relate Objects and ObjectTypes to the "ObjectTypes" standard Object. The "ObjectTypes" Object shall not reference any other NodeClasses.

Figure 4 – ObjectTypes organization

The intention of the "ObjectTypes" Object is that all ObjectTypes of the Server are either directly or indirectly accessible browsing HierarchicalReferences starting from this Node. However, this is not required and Servers might not provide some of their ObjectTypes because they may be well-known in the industry, such as the ServerType defined in 6.3.1.

This Object also indirectly references the BaseEventType defined in 6.4.2, which is the base type of all EventTypes. Thereby it is the entry point for all EventTypes provided by the Server. It is required that the Server expose all its EventTypes, so a client can usefully subscribe to Events.

The "ObjectTypes" Object is formally defined in Table 100.

Table 100 – ObjectTypes definition

Attribute	Value
BrowseName	ObjectTypes
References		NodeClass	BrowseName	Comment
HasTypeDefinition		ObjectType	FolderType	Defined in 6.6
Organizes		ObjectType	BaseObjectType	Defined in 6.2
Conformance Units
Base Info Core Types Folders