diff --git a/Instruction-Set.md b/Instruction-Set.md
index 438283a..bf75aee 100644
--- a/Instruction-Set.md
+++ b/Instruction-Set.md
@@ -272,6 +272,9 @@ destination & source      # flags will be set
     destination and updates the flags. None of the operands are
     changed.
 
+> ? TODO: is this implemented correctly?
+> I see differing results using test/jz vs cmp/jnz that seem to involve overflow from the latter?
+
 
 #### Pseudo code
 ```py
@@ -593,4 +596,3 @@ dest = ~dest
 ```
 
 ## Encoding
-