Web Inspector: ER: DOM node 'Issues' list for errors and warnings. Node properties could have a sub-section listing errors and warnings for the selected DOM node. For example, general validation errors, elements missing required attributes or attributes with invalid values. Also accessibility errors including headings or links with missing text or text alternatives, or label@for IDREFs to form elements that don't exist in the DOM. May also want a feature (probably a second bug) to "run all checks recursively from the root node" and log to the console. That kind of audit could take a while though, so probably best not to enable the recursive checks by default.
<rdar://problem/14335369>
related to bug 149614