[1] Synchronized Multimedia Integration Language (1998-06-16 04:11:22 +09:00 版) http://www.w3.org/TR/1998/REC-smil-19980615/#switch
[4] Document Structure – SVG 1.1 (Second Edition) ( (2011-08-10 12:35:27 +09:00 版)) http://www.w3.org/TR/2011/REC-SVG11-20110816/struct.html#ConditionalProcessing
[2] systemLanguage
systemLanguage