diff --git a/reference/var/functions/isset.xml b/reference/var/functions/isset.xml
index 27eccffc6c..22289269d5 100644
--- a/reference/var/functions/isset.xml
+++ b/reference/var/functions/isset.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.18 $ -->
+<!-- $Revision: 1.19 $ -->
 <refentry xml:id="function.isset" xmlns="http://docbook.org/ns/docbook">
  <refnamediv>
   <refname>isset</refname>
@@ -23,6 +23,11 @@
    variable that has been set to &null;. Also note that a &null; byte
    (<literal>"\0"</literal>) is not equivalent to the PHP &null; constant.
   </para>
+  <para>
+   If multiple parameters are supplied then <function>isset</function> will
+   return &true; only if all of the parameters are set. Evaluation goes from
+   left to right and stop as soon as a set variable is encountered.
+  </para>
  </refsect1>
 
  <refsect1 role="parameters">