diff -r 83cea5dc6bac -r 9a6e5e0c4906 CookBook/Readme.thy
--- a/CookBook/Readme.thy	Thu Jan 08 22:46:06 2009 +0000
+++ b/CookBook/Readme.thy	Thu Jan 08 22:47:15 2009 +0000
@@ -14,7 +14,8 @@
   \end{center}
 
   You very likely need a recent snapshot of Isabelle in order to compile
-  the Cookbook.
+  the Cookbook. Some parts of the Cookbook also rely on compilation with
+  PolyML.
 
   \item You can include references to other Isabelle manuals using the 
   reference names from those manuals. To do this the following