Bugzilla – Bug 881
Allow the empty string in the "value" attribute on input element where spec requires
Last modified: 2012-11-18 13:22:32 CET
see http://www.w3.org/Bugs/Public/show_bug.cgi?id=14876
http://html5.org/r/6118
https://github.com/validator/syntax/commit/f55a8abe68315f8d331ac987d896cfb31be3ef0d