<its:rules xmlns:its="http://www.w3.org/2005/11/its" version="2.0">
<its:param name="withinTextParam">footnote</its:param>
<its:withinTextRule withinText="yes" selector="//b|//u|//i"/>
<its:withinTextRule withinText="nested" selector="//fn[@id=$withinTextParam]"/>
</its:rules>