diff --git a/implementations/rust/src/lib.rs b/implementations/rust/src/lib.rs
index 82407a4..b74fc75 100644
--- a/implementations/rust/src/lib.rs
+++ b/implementations/rust/src/lib.rs
@@ -9,6 +9,8 @@ mod ieee754_section_5_10_total_order_tests {
     fn f(val: f32) -> Value { Value::from(val) }
     fn d(val: f64) -> Value { Value::from(val) }
 
+    // TODO: Test cases with a few different signalling and non-signalling NaNs
+
     #[test] fn case32_a_1() { assert_eq!(f(1.0).cmp(&f(2.0)), Less) }
     #[test] fn case32_a_2() { assert_eq!(f(-1.0).cmp(&f(1.0)), Less) }
     #[test] fn case32_a_3() { assert_eq!(f(0.0).cmp(&f(1.0)), Less) }