diff --git a/Common-Criticisms.md b/Common-Criticisms.md
index 8efa755..1cb5218 100644
--- a/Common-Criticisms.md
+++ b/Common-Criticisms.md
@@ -6,7 +6,7 @@ Possibly. The problem here is that of what mental metaphor is being used. In man
 ``` nimrod
 proc foo(input: var T) = ...
 proc foo(input: ref T) = ...
-let a: ref T = ...
+let a: ref T = ...  # `let` says the value of the pointer is immutable
 foo(a)  # valid, this is Java-style
 var b: T = ...
 foo(b)  # also valid