title: Using ID with CLASS in a tag
body: <p>I would like to mark a tag with an id in HTML like this:</p>
  
  <pre><code>&lt;span id="id_errortag" 
      style="font-family:Helvetica;Font-size:14px;" class="red"&gt;&lt;/span&gt;
  </code></pre>
  
  <p>I want to find out whether this is ok by HTML standards to use an id in conjunction with a class? </p>