added note warning about use of placeholder as a label

Hi all,

after recent discussion on list [1] I made some changes [2] in the 5.1 spec
[3] to warn that use of placeholder as a label can reduce accessibility and
usability

Note: Use of the placeholder
> <http://www.w3.org/html/wg/drafts/html/master/forms.html#attr-input-placeholder>attribute as a replacement for a
> label<http://www.w3.org/html/wg/drafts/html/master/forms.html#the-label-element>can reduce the accessibility and usability of the control for a range of
> users including
> older users and users with cognitive, mobility or vision impairments.
>

I also removed recommendation about using the title attribute for a longer
hint advising instead to place it as text next to the control.

Please review at your leisure, feedback welcome and appreciated.


[1] http://lists.w3.org/Archives/Public/public-html/2013Feb/0164.html
[2]
https://github.com/w3c/html/commit/247c0c041dfdb7b9a760969872d35025cd6d90da
[3]
http://www.w3.org/html/wg/drafts/html/master/forms.html#the-placeholder-attribute

-- 
with regards

Steve Faulkner
Technical Director - TPG

www.paciellogroup.com | www.HTML5accessibility.com |
www.twitter.com/stevefaulkner
HTML5: Techniques for providing useful text alternatives -
dev.w3.org/html5/alt-techniques/
Web Accessibility Toolbar - www.paciellogroup.com/resources/wat-ie-about.html