Bugzilla – Bug 955
option label attribute must not be empty; option with no label must have content
Last modified: 2013-07-15 10:24:33 CEST
http://html5.org/r/7622 http://www.whatwg.org/specs/web-apps/current-work/multipage/the-button-element.html#attr-option-label "The label content attribute, if specified, must not be empty. If the attribute is not specified, then the element itself must not be empty."
https://bitbucket.org/validator/syntax/commits/83a2871964928e5acb9013e24d461d1f98852505