diff --git a/docs/manual/CoreTypes/custom-programming.html b/docs/manual/CoreTypes/custom-programming.html
index e8366f715..d6c1e9830 100644
--- a/docs/manual/CoreTypes/custom-programming.html
+++ b/docs/manual/CoreTypes/custom-programming.html
@@ -39,6 +39,8 @@
     <p>
       After the class has been written, it is added to the ant system
       by using <code>&lt;typedef&gt;</code>.
+      One thing to be aware of is that currently this will only work
+      if the definition name is all lower case.
     </p>
     <h3><a name="customconditions">Custom Conditions</a></h3>
     <p>