[1]

値	よく使われる場所	状態	出典
(空文字列)	(既定値)	W3C 勧告	MathML
Maple	annotation	W3C 勧告 (例)	MathML
Mathmatica	annotation	W3C 勧告 (例)	MathML
MathML-Content	annotation-xml	W3C 勧告	MathML
MathML-Presentation	annotation-xml	W3C 勧告	MathML
OpenMath	annotation-xml	W3C 勧告 (例)	MathML
TeX	annotation	W3C 勧告 (例)	MathML
text/html	annotation-xml	WHATWG 標準案	>>4
application/xhtml+xml	annotation-xml	WHATWG 標準案	>>4

[2] annotation-xml and annotation encoding (Henri Sivonen 著, 2007-12-17 17:23:36 +09:00 版) http://lists.w3.org/Archives/Public/www-math/2007Dec/0002.html

[4] Web Applications 1.0 - HTML統合点 http://www.whatwg.org/specs/web-apps/current-work/complete.html#html-integration-point

[5] XQuery 1.0: An XML Query Language (Second Edition) ( (2011-01-05 01:29:08 +09:00 版)) http://www.w3.org/TR/2010/REC-xquery-20101214/#dt-encoding-declaration

[6] IRC logs: freenode / #whatwg / 20130419 ( (2013-05-01 23:09:17 +09:00 版)) http://krijnhoetmer.nl/irc-logs/whatwg/20130419#l-723

[7] XQuery 3.0: An XML Query Language ( (2014-04-08 08:26:21 +09:00 版)) http://www.w3.org/TR/xquery-30/#dt-encoding-declaration