Four tests suggest form elements require a valid "tabindex" attribute. I believe this is not correct. In almost all circumstances, WebAIM recommends against using tabindex(http://webaim.org/techniques/keyboard/tabindex). The best way to fix tab order and reading order is to use focusable HTML elements wherever possible andalter the order of the content in the markup itself, rather than try to hide the problem by using tabindex, then use CSS, if needed, to control the visual presentation. See also (http://www.paciellogroup.com/blog/2014/08/using-the-tabindex-attribute/)
Four tests suggest form elements require a valid "tabindex" attribute. I believe this is not correct. In almost all circumstances, WebAIM recommends against using tabindex(http://webaim.org/techniques/keyboard/tabindex). The best way to fix tab order and reading order is to use focusable HTML elements wherever possible andalter the order of the content in the markup itself, rather than try to hide the problem by using tabindex, then use CSS, if needed, to control the visual presentation. See also (http://www.paciellogroup.com/blog/2014/08/using-the-tabindex-attribute/)