A References

IETF RFC 2119
RFC 2119: Key words for use in RFCs to Indicate Requirement Levels. Internet Engineering Task Force, 1997. (See http://www.ietf.org/rfc/rfc2119.txt.)
IETF RFC 3629
RFC 3629: UTF-8, a transformation format of ISO 10646. Internet Engineering Task Force, 2003. (See http://www.ietf.org/rfc/rfc3629.txt.)
IETF RFC 2396
RFC 2396: Uniform Resource Identifiers. Internet Engineering Task Force, 1995. (See http://www.ietf.org/rfc/rfc2396.txt.)
IETF RFC 2732
RFC 2732: Format for Literal IPv6 Addresses in URL's. Internet Engineering Task Force, 1999. (See http://www.ietf.org/rfc/rfc2732.txt.)
IETF RFC 3023
RFC 3023: XML Media Types. Internet Engineering Task Force, 2001. (See http://www.ietf.org/rfc/rfc3023.txt.)
IETF RFC 3987
RFC 3987: Internationalized Resource Identifiers (IRIs). Internet Engineering Task Force, 2005. (See http://www.ietf.org/rfc/rfc3987.txt.)
Unicode
The Unicode Consortium. The Unicode Standard, Version 4.0. Reading, Mass.: Addison-Wesley, 2003, as updated from time to time by the publication of new versions. (See http://www.unicode.org/unicode/standard/versions/ for the latest version and additional information on versions of the standard and of the Unicode Character Database).
XML 1.0
Tim Bray, Jean Paoli, C.M. Sperberg-McQueen, Eve Maler, François Yergeau, editors. Extensible Markup Language (XML) 1.0 (Third Edition), World Wide Web Consortium, 2004. (See http://www.w3.org/TR/2004/REC-xml-20040204/.)
XML 1.1
Tim Bray, Jean Paoli, C.M. Sperberg-McQueen, Eve Maler, François Yergeau, John Cowan, editors. Extensible Markup Language (XML) 1.1, World Wide Web Consortium, 2004. (See http://www.w3.org/TR/2004/REC-xml11-20040204/.)
XML Base
Jonathan Marsh, editor. XML Base. World Wide Web Consortium, 2001. (See http://www.w3.org/TR/2001/REC-xmlbase-20010627/.)
XML Information Set
John Cowan and Richard Tobin, editors. XML Information Set (Second Edition). World Wide Web Consortium, 2004. (See http://www.w3.org/TR/2004/REC-xml-infoset-20040204/.)
Namespaces in XML
Tim Bray, Dave Hollander, and Andrew Layman, editors. Namespaces in XML. World Wide Web Consortium, 1999. (See http://www.w3.org/TR/1999/REC-xml-names-19990114/.)
Namespaces in XML 1.1
Tim Bray, Dave Hollander, Andrew Layman, Richard Tobin, editors. Namespaces in XML 1.1. World Wide Web Consortium, 2004. (See http://www.w3.org/TR/2004/REC-xml-names11-20040204/.)
XPointer Framework
Paul Grosso, Eve Maler, Jonathan Marsh, Norman Walsh, editors. XPointer Framework. World Wide Web Consortium, 2003. (See http://www.w3.org/TR/2003/REC-xptr-framework-20030325/.)
XPointer element() scheme
Paul Grosso, Eve Maler, Jonathan Marsh, Norman Walsh, editors. XPointer element() Scheme. World Wide Web Consortium, 2003. (See http://www.w3.org/TR/2003/REC-xptr-element-20030325/.)