The UriDictionaryEntryType defined in Table 4 is used to represent dictionary entries that use URIs as unique identifiers.

Table 4 – UriDictionaryEntryType Definition

Attribute	Value
BrowseName	UriDictionaryEntryType
IsAbstract	False
References	NodeClass	BrowseName	DataType / TypeDefinition	ModellingRule
Subtype of the DictionaryEntryType defined in 5.1.
Conformance Units
Address Space Dictionary URI

The identifier in the respective external dictionary shall be a unique URI string. This identifier is used for the NodeId and the BrowseName Attributes of instances of the DictionaryEntryType. The IdentifierType of the NodeId shall be STRING_1 with the identifier from the external dictionary as the value.

The namespace “http://opcfoundation.org/UA/Dictionary/URI” shall be used for instance of the UriDictionaryEntryType. Subtypes may define different namespaces.

The identifier shall be immutable; meaning that it shall not be reassigned to a different dictionary entry within the scope of the namespace in future versions. Data dictionaries may be publicly defined by standard bodies such as IEC or proprietary (e.g. vendor-specific dictionaries).