diff --git a/src/circuit/pedersen_hash.rs b/src/circuit/pedersen_hash.rs
index c540a23..55f9cfb 100644
--- a/src/circuit/pedersen_hash.rs
+++ b/src/circuit/pedersen_hash.rs
@@ -10,6 +10,7 @@ use bellman::{
 };
 use super::lookup::*;
 
+// TODO: ensure these match the spec
 pub enum Personalization {
     NoteCommitment,
     AnotherPersonalization