title: How should user agents handle the HTML5 required attribute?
body: <p>This is probably a bit of a noob question, so apologies in advance but...Does the HTML5 specification define how user agents should respond to the HTML5 required attribute (or is it up to them)? In other words, are there any <em>concrete</em> rules that define how user agents should behave (e.g. "users should be alerted to the presence of a required field"; "when the user submits the form, required controls should be validated and error messages displayed in the event that they do not possess a value"; etc.)</p>
  
  <p>The HTML5 spec seems to provide some vague guidelines but nothing concrete.</p>