joomla/joomla-cms — pull request #2294 by piotrmocko (2013-10-20 13:12:30+00:00)
Title: Improved and simplified radio and checkbox validation with jQuery valida...

...tor

Still backward compatible but much easier to use. You do not have to add any ID's to input elements.
More description in old tracker item:
http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_id=8103&tracker_item_id=26114