<!DOCTYPE html>
<html>
<head>
  <meta charset=utf-8>
  <title>&lt;bdo&gt;</title>
</head>
<body>
  <!-- is structured inline; requires 'dir', test all attrs -->
  <p><bdo dir="ltr"
          lang="en"
          style=""
          class="class"
          id="foo">text</bdo></p>

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

  <!-- can be empty -->
  <p>text <bdo dir="ltr"></bdo></p>
  <p>text <dfn><bdo dir="ltr"></bdo></dfn></p>

  <!-- can contain interactive -->
  <p><bdo dir="ltr"><a>text</a></bdo></p>
  <p><dfn><bdo dir="ltr"><a>text</a></bdo></dfn></p>

  <!-- cannot contain structured inline -->
</body>
</html>