[1] Extensible Markup Language (XML) 1.1 (Second Edition) ( (2006-09-29 19:02:09 +09:00 版)) <http://www.w3.org/TR/2006/REC-xml11-20060816/#sec-CharNorm>

[2] Character Model for the World Wide Web 1.0: Fundamentals ( (2005-02-15 14:24:00 +09:00 版)) <http://www.w3.org/TR/charmod/#Unicode_Encoding_Form>