 
<!DOCTYPE html>
<html>

<head>
  <title>Six Levels of Headings in XHTML</title>
</head>

<body>
  <h1>Heading 1</h1>
  <h2>Heading 2</h2>
  <h3>Heading 3</h3>
  <h4>Heading 4</h4>
  <h5>Heading 5</h5>
  <h6>Heading 6</h6>
</body>
</html>