The XDS.b Integration Profile is part of the family of XDS profiles. It supports these features (in comparison to XDS.a): <ul><li>Change in the XDS metadata form from ebXML Reg/Rep RIM 2.1 to version 3.0</li><li>A new repositoryUniqueId attribute added to the XDS metadata</li><li>Definition of a new transaction &quot;Retrieve Document Set&quot; as a new binding for the XDS.a Retrieve Document [ITI-17] transaction</li><li>Definition of updated bindings for existing transactions to reflect changes in the web services specifications</li></ul>