XQuery Update Facility
XQuery Update Facility is an extension to the XML Query language, XQuery. It provides expressions that can be used to make changes to instances of the XQuery 1.0 and XPath 2.0 Data Model. It became a W3C Candidate Recommendation on 31 July 2009 and was finalised as Recommendation on 17 March 2011. A version to work with XQuery 3.0 was drafted, but was never completed, and is archived as a W3C Working Group Note.