Update Site for W3C Compliance

We have a report for W3C compliance for a prototype site. Before we go live everything considered "Known Problems" and "likely Problems" need to be fixed. Please try to make all updates (without affecting the presentation of the front end, if its a color contrast change that's fine or changing the tag of text that's fine its more structure changes) please make ongoing checks to make sure front end is not adversely affected. Also please provide an update at the end of the day.