W3C XML, Extensible Markup Language (XML) 1.0 (Second Edition), W3C Recommendation, 6 October 2000, available at http://www.w3.org/TR/2000/REC-xml-20001006.

W3C XML-InfoSet, XML Information Set, W3C Recommendation 24 October 2001, available at http://www.w3.org/TR/xml-infoset/.

W3C XML-Names, Namespaces in XML, W3C Recommendation, 14 January 1999, available at http://www.w3. org/TR/1999/REC-xml-names-19990114.

W3C XML-Fragments, XML Fragment Interchange, W3C Candidate Recommendation 12 February 2001, available at http://www.w3.org/TR/xml-fragment.

RFC 2119 [Keywords], Key words for use in RFCs to Indicate Requirement Levels, S. Bradner. Best Current Practice, March 1997, available at http://www.ietf.org/rfc/rfc2119.txt.