Index: constants.xml
===================================================================
RCS file: /repository/phpdoc/en/language/constants.xml,v
retrieving revision 1.43
diff -u -r1.43 constants.xml
--- constants.xml	7 Mar 2006 00:29:13 -0000	1.43
+++ constants.xml	11 Jun 2006 08:36:38 -0000
@@ -62,7 +62,8 @@
    <simpara>
     You can define a constant by using the 
     <function>define</function>-function. Once a constant is defined,
-    it can never be changed or undefined.
+    it can never be changed or undefined. Unlike functions, constants need to
+    be defined before they are referenced.
    </simpara>
    <simpara>
     Only scalar data (<type>boolean</type>, <type>integer</type>,