Repair markup

doc/src/sgml/datatype.sgml

 <!--
-$Header: /cvsroot/pgsql/doc/src/sgml/datatype.sgml,v 1.40 2000/11/11 19:50:31 thomas Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/datatype.sgml,v 1.41 2000/11/11 23:27:48 petere Exp $
 -->
 
  <chapter id="datatype">
@@ -1908,8 +1908,8 @@ January 8 04:05:06 1999 PST
     </para>
    </sect2>
 
-   <sect2 id="inet-type">
-    <title><type>inet</type></title>
+   <sect2 id="inet-vs-cidr">
+    <title><type>inet</type> vs <type>cidr</type></title>
 
     <para>
     The essential difference between <type>inet</type> and <type>cidr</type>