title: Unescaped xml character
body: <p>My IDE (<code>phpstorm</code>) complains that this contains an <code>Unescaped xml character</code>.
  This has been bugging me for a while:</p>
  
  <pre><code>&lt;? } if (isset($_GET[id])) { ?&gt;
      document.getElementById("facebook_likebutton").innerHTML = '&lt;';
  &lt;? } ?&gt;
  </code></pre>
  
  <p>it marks the <code>'&lt;'</code> as the part where its an error.</p>
  
  <p>see this image:</p>
  
  <p><img src="https://i.stack.imgur.com/EHCVh.png" alt="enter image description here"></p>