diff --git a/TODO b/TODO
index 437530c..31cf4a8 100644
--- a/TODO
+++ b/TODO
@@ -61,8 +61,8 @@
 
 - Add:  .define foo = ! string
 
-- Recursive .define replacements
-  
+- Recursive .define replacements with loop detection and explain how
+  to use to override bultins.  
 
 - Do testmode substitions.