The types and instances defined in this document are illustrated in Figure 1. The DictionaryEntryType is an abstract base type for dictionary entries. The IrdiDictionaryEntryType and the UriDictionaryEntryType provide concrete types that can be used to represent dictionary entries. The HasDictionaryEntry ReferenceType is used to refer an OPC UA Node to a dictionary entry. The DictionaryFolderType and the Dictionaries Object provide an optional capability to expose the hierarchy of a referenced dictionary.