The namespace whose name is http://www.w3.org/XML/1998/namespace is bound by definition to the prefix xml: according to Namespaces in XML, W3C Recommendation 14 Jan 1999 (and by Namespaces in XML 1.1). Note that unlike all other XML namespaces, both the name and the prefix are specified; i.e., if you want XML 1.0 processors to recognize this namespace, you must use the reserved prefix xml:. xml The official description of the "xml:" namespace as provided by the W3C. W3C, http://www.w3.org/ 2006-01-08 released