diff --git a/appendices/debugger.xml b/appendices/debugger.xml
index e747bd8ca3..a487c1faf5 100644
--- a/appendices/debugger.xml
+++ b/appendices/debugger.xml
@@ -1,6 +1,16 @@
  <appendix id="debugger">
   <title>The PHP Debugger</title>
 
+  <sect1 id="debugger-about">
+   <title>About the debugger</title>
+   <simpara>
+    PHP 3 includes support for a network-based debugger.
+   </simpara>
+   <simpara>
+    PHP 4 does not yet have a similar debugging facility.
+   </simpara>
+  </sect1>
+
   <sect1 id="debugger-using">
    <title>Using the Debugger</title>