&lt;!DOCTYPE para PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
          "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"&gt;
&lt;para&gt;
The Tiger&lt;indexterm&gt;
&lt;primary&gt;Big Cats&lt;/primary&gt;
&lt;secondary&gt;Tigers&lt;/secondary&gt;&lt;/indexterm&gt;
is a very large cat indeed.
&lt;/para&gt;