<!DOCTYPE html>
<html>
<head>
  <meta charset=utf-8>
  <title>&lt;pre&gt;</title>
</head>
<body>
  <!-- is block -->
  <pre class="class" id="id" lang="en">text</pre>

  <!-- is structured inline -->
  <p>paragraph
    <pre>text</pre>
  </p>

  <!-- can contain interactive -->
  <pre><a>text</a></pre>
  <!-- but not struct-inline -->
  <p>paragraph
    <pre><a>text</a></pre>
  </p>

  <!-- can contain strictly inline -->
  <pre>text <em>elem</em></pre>
</body>
</html>