Normative references

[RFC 2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, <http://www.rfc-editor.org/info/rfc2119>.
[RFC 3986]
Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, DOI 10.17487/RFC3986, January 2005, <http://www.rfc-editor.org/info/rfc3986>.
[RFC 5646]
Phillips, A., Ed., and M. Davis, Ed., "Tags for Identifying Languages", BCP 47, RFC 5646, DOI 10.17487/RFC5646, September 2009, <http://www.rfc-editor.org/info/rfc5646>.
[XML 1.0]
Extensible Markup Language (XML) 1.0 (Fifth Edition), T. Bray, J. Paoli, M. , E. Maler, F. Yergeau, Editors, W3C Recommendation, 26 November 2008, http://www.w3.org/TR/2008/REC-xml-20081126/ . Latest version available at http://www.w3.org/TR/xml .
[XML 1.1]
Extensible Markup Language (XML) 1.1 (Second Edition), T. Bray, J. Paoli, M. , E. Maler, F. Yergeau, J. Cowan, Editors, W3C Recommendation, 16 August 2006, http://www.w3.org/TR/2006/REC-xml11-20060816/ . Latest version available at http://www.w3.org/TR/xml11/ .