歴史

[1] Safari Dev Center: Safari HTML Reference: Supported Input Values (2010-03-20 18:30:44 +09:00 版) http://developer.apple.com/safari/library/documentation/AppleApplications/Reference/SafariHTMLRef/Articles/InputTypes.html#//apple_ref/doc/uid/TP40008055-SW4

[2] [whatwg] Changing punctuation value of input element in telephone state (2010-07-29 07:31:03 +09:00 版) http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2010-July/027404.html

[3] Opera: Opera 11.00 for Windows changelog ( (Frank M. Palinkas, Technical Writer, Opera Software ASA 著, 2011-04-24 11:17:12 +09:00 版)) http://www.opera.com/docs/changelogs/windows/1100/