The identifier pattern must match the URI pattern.1
It may match the identifier pattern given by OAIPMh 2.
This would require a change in the projects using the cube.
http://www.openarchives.org/OAI/openarchivesprotocol.html#UniqueIdentifier ↩
http://www.openarchives.org/OAI/2.0/guidelines-oai-identifier.htm, http://www.openarchives.org/OAI/2.0/oai-identifier.xsd ↩