My local HTML validator is warning me that:
<div id="10_reasons">
is invalid due to the name beginning with a digit, which is invalid. The html is coming out of our Matrix install. Is there any way to get Matrix to check Div names prior to a commit and require the end user to correct those that are invalid?
Matrix does not have this feature. There are many places where you can define DIV names and IDs besides standard page editing, so it is best to make a full-page accessibility check part of your editing process. You will need to use one of the 3rd party checkers though. Matrix will only check WYSIWYG content for common errors and not the page as a whole.