diff --git a/Doc/Sdi/dns.xml b/Doc/Sdi/dns.xml
index 0f33f56f1644f162d313d0c6f8db8a17515728b8..01b8d5430c10acadba2c280fbbc0fcbeff626734 100644
--- a/Doc/Sdi/dns.xml
+++ b/Doc/Sdi/dns.xml
@@ -48,6 +48,26 @@
         </glossdef>
       </glossentry>
 
+      <glossentry>
+        <glossterm>Log level</glossterm>
+
+        <glossdef>
+          <para>For debugging purposes you may want to adjust the server's log
+          level:</para>
+
+          <programlisting>logging {
+   channel querylog{
+         syslog;
+         <emphasis role="bold">severity debug 10;
+         print-category yes;
+         print-time yes;
+         print-severity yes;</emphasis>
+    };
+    category queries { querylog;};
+};</programlisting>
+        </glossdef>
+      </glossentry>
+
       <glossentry>
         <glossterm>Configure server startup</glossterm>