diff --git a/basic_timing_cache_channel/src/lib.rs b/basic_timing_cache_channel/src/lib.rs
index 462e05a..afb856b 100644
--- a/basic_timing_cache_channel/src/lib.rs
+++ b/basic_timing_cache_channel/src/lib.rs
@@ -44,7 +44,7 @@ pub trait TimingChannelPrimitives: Debug + Send + Sync + Default {
 #[derive(Debug)]
 pub struct TopologyAwareTimingChannelHandle {
     threshold: Threshold,
-    vpn: VPN,
+    vpn: VPN, // what is this field used for
     addr: *const u8,
     ready: bool,
     calibration_epoch: usize,
@@ -488,6 +488,8 @@ impl<T: TimingChannelPrimitives> MultipleAddrCacheSideChannel for TopologyAwareT
         operation(); // TODO use a different helper core ?
     }
 
+    // this function tolerates multiple handle on the same cache line
+    // should the invariant be fixed to one handle per line & calibration epoch ?
     unsafe fn calibrate(
         &mut self,
         addresses: impl IntoIterator<Item = *const u8> + Clone,
diff --git a/basic_timing_cache_channel/src/naive.rs b/basic_timing_cache_channel/src/naive.rs
index 7e87864..dcb98ed 100644
--- a/basic_timing_cache_channel/src/naive.rs
+++ b/basic_timing_cache_channel/src/naive.rs
@@ -22,7 +22,7 @@ pub struct NaiveTimingChannel<T: TimingChannelPrimitives> {
 }
 
 pub struct NaiveTimingChannelHandle {
-    vpn: VPN,
+    vpn: VPN, // what is this field used for
     addr: *const u8,
 }
 
@@ -83,6 +83,10 @@ impl<T: TimingChannelPrimitives> NaiveTimingChannel<T> {
         }
     }
 
+    // The former invariant of one handle per page has been removed
+    // Now tolerates as many handles per cache line as wanted
+    // should the invariant be fixed into one handle per cache line ?
+
     unsafe fn calibrate_impl(
         &mut self,
         addr: *const u8,