title: Is an empty class attribute valid HTML?
body: <p>Is an empty <code>class</code> attribute valid HTML in the following formats:</p>
  
  <pre><code>&lt;p class=""&gt;something&lt;/p&gt;
  &lt;p class&gt;something&lt;/p&gt;
  </code></pre>
  
  <p>I found <a href="https://stackoverflow.com/questions/9729080/are-empty-html5-data-attributes-valid">this question</a> which is similar, but asks specifically about custom data attributes.</p>