title: breadcrumb in OSClass
body: <p>I'm new for OSClass.
  I saw</p>
  
  <p><code>$breadcrumb = osc_breadcrumb('&amp;raquo;', false);</code> </p>
  
  <p>in <code>header.php</code>. Where <code>osc_breadcrumb()</code> is define? I'm using <code>modern</code> theme.</p>