<!DOCTYPE html>
<html>
<head>
  <meta charset=utf-8>
  <title>&lt;span&gt;</title>
</head>
<body>
  <!-- is structured inline -->
  <p><span class="class" lang="en">text</span></p>

  <!-- is strictly inline -->
  <p><dfn><span class="class" lang="en">text</span></dfn></p>

  <!-- can be empty -->
  <p>text <span></span></p>
  <p>text <dfn><span></span></dfn></p>

  <!-- can contain interactive -->
  <p><span><a>text</a></span></p>
  <p><dfn><span><a>text</a></span></dfn></p>

</body>
</html>