When using proprietary identifiers, the sender needs to be able to provide a namespace attribute to signal which organisation the proprietary identification is controlled by (as the organisation may not be the one allocating or sending the message).
Thus, a proprietary sound recording identifier could look like:
As with the namespaces for user-defined values, the
Namespace attribute for a proprietary identifier should contain the DPID (without a namespace prefix) of the organisation controlling the identifier system used. Typically, this will be the organisation that sends the DDEX message or a company that has forwarded the identifier to the message sender.
In some cases, however, the identifier has been allocated by a company or service who are not part of the information exchange. MusicBrainz is one such example. To enable identifiers allocated by such organisations to be communicated in DDEX messages, DDEX will allocate DPIDs to them. MusicBrainzId were allocated
PADPIDA2014032102X, for instance.
The example below shows how the MusicBrainzId for the Cranberries’ recording of “Zombie” can be communicated using this method:
As a consequence of the above, it is possible to find the namespace value for such identification systems in the DDEX Party Identifier Repository which all users of the DDEX standard have access to.