Index: head/en_US.ISO8859-1/books/fdp-primer/xml-primer/chapter.xml
===================================================================
--- head/en_US.ISO8859-1/books/fdp-primer/xml-primer/chapter.xml
+++ head/en_US.ISO8859-1/books/fdp-primer/xml-primer/chapter.xml
@@ -861,7 +861,7 @@
 	  context</link>.</para>
 
       <para>Parameter entity definitions are similar to those for
-	general entities.  However, parameter entries are included
+	general entities.  However, parameter entities are included
 	with
 	<literal>%<replaceable>entity-name</replaceable>;</literal>.
 	The definition also includes the <literal>%</literal> between
@@ -877,13 +877,16 @@
 
 	<programlisting>&lt;!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd" [
-&lt;!ENTITY % param.some "some"&gt;
-&lt;!ENTITY % param.text "text"&gt;
-&lt;!ENTITY % param.new  "%param.some more %param.text"&gt;
-
-&lt;!-- %param.new now contains "some more text" --&gt;
+&lt;!ENTITY % entity "&lt;!ENTITY version '1.0'&gt;"&gt;
+&lt;!-- use the parameter entity --&gt;
+%entity;
 ]&gt;</programlisting>
       </example>
+
+      <para>At first sight, parameter entities do not look very
+	useful, but they make it possible to <link
+	  linkend="xml-primer-include">include other files</link> into
+	an XML document.</para>
     </sect2>
 
     <sect2 xml:id="xml-primer-to-do">