div class="alert alert-info">
You can check whether a control is legitimately disabled for a screen reader by visiting
<a href="chrome://accessibility">chrome://accessibility</a> and inspecting <a href="http://www.paciellogroup.com/blog/2015/01/the-browser-accessibility-tree/">the accessibility tree</a>.
</div>

<h2 id="ngrequired">ngRequired</h2>

<p>The boolean <code>required</code> attribute is only valid for native form controls such as <code>input</code> and
<code>textarea</code>. To properly indicate 