<?xml version="1.0"?>

<doc xmlns:xi="http://www.w3.org/2001/XInclude">

<caveat><para>This is a caveat that we repeat often.</para></caveat>

<section>
<title>A</title>
 <xi:include xpointer="xpointer(//caveat[1])"/>
</section>

<section>
<title>B</title>
<xi:include  xpointer="xpointer(/doc/caveat)"/> 
</section>

</doc>