<doc>
 <head>
  <its:rules version="2.0" xmlns:its="http://www.w3.org/2005/11/its">
   <its:withinTextRule withinText="yes" selector="//b|//u|//i"/>
   <its:withinTextRule withinText="nested" selector="//fn"/>
  </its:rules>
 </head>
  <body>
   <p>This is a paragraph with <b>bold</b>, <i>italic</i>, and <u>underlined</u>.</p>
   <p>This is a paragraph with a footnote<fn>This is the text of the footnote</fn> at the middle.</p>
  </body>
 </doc>