diff --git a/Doc/Sda1/dom.xml b/Doc/Sda1/dom.xml
index 112d35bb9bf14907d974add30ec6ac9801cf36e9..5f31d93fbba9ff77c08dc7803bf553a603808000 100644
--- a/Doc/Sda1/dom.xml
+++ b/Doc/Sda1/dom.xml
@@ -1193,13 +1193,17 @@ public class CheckUrl {
               xlink:href="http://www.w3.org/TR/xpath">XPath</acronym>
               expression:</para>
 
-              <programlisting language="none">//html:img[starts-with(@src, 'http://') or starts-with(@src, 'https://') or starts-with(@src, 'ftp://')]</programlisting>
-
-              <para><xref linkend="glo_XHTML"/> Namespace handling is
-              essential with respect to <acronym
-              xlink:href="http://www.w3.org/TR/xpath">XPath</acronym>
-              expressions. We thus define a corresponding namespace prefix
-              <code>xhtml</code>:</para>
+              <programlisting language="none">//xhtml:img[starts-with(@src, 'http://') or starts-with(@src, 'https://') or starts-with(@src, 'ftp://')]</programlisting>
+
+              <para> Notice the prefix <quote>xhtml</quote> in the above
+              <acronym
+              xlink:href="http://www.w3.org/TR/xpath">XPath</acronym>.
+              Namespace handling is essential since our elements belong to the
+              <xref linkend="glo_XHTML"/> namespace. We thus create a
+              corresponding <classname
+              xlink:href="http://www.jdom.org/docs/apidocs/org/jdom2/Namespace.html">Namespace</classname>
+              instance along with the desired <code>xhtml</code>
+              prefix:</para>
 
               <programlisting language="none">final Namespace htmlNamespace = // This will allow for XPath expressions like xhtml:img
             Namespace.getNamespace("xhtml", "http://www.w3.org/1999/xhtml");