About XQuery 1.0 and XPath 2.0 Data Model (XDM) (Second Edition)
XQuery 1.0 and XPath 2.0 Data Model (XDM) (Second Edition)- This document defines the W3C XQuery 1.0 and XPath 2.0 Data Model, which is the data model of at least XSLT and XQuery, and any other specifications that reference it. This data model is based on the data models of XPath and XML Query Data Model and replaces XML Query Data Model. (W3C Recommendation 14 December 2010)