One of the design goals associated with the UDDI registration data is the ability to mark information with identifiers. The purpose of identifiers in the UDDI registration data, namely for businessEntity and tModel instances, is to allow others to find the published information using more formal identifier systems. For example, businesses may want to use their D-U-N-S (Dun & Bradstreet's Data Universal Numbering System), Global Location Number (GLN), or tax identifier in their UDDI registration data, since these identifiers are shared in a public or private community in order to unambiguously identify businesses. In UDDI registries that are only used in private communities, businesses may also want to use privately known identifiers.
The «identifier» element contains a string or number used to uniquely identify a standard document or a statement. In the ASN, the value of the «identifier» property is always a URI. In RDF, this value is expressed most frequently as "rdf:about".