diff --git a/crates/loro-internal/src/state/movable_list_state.rs b/crates/loro-internal/src/state/movable_list_state.rs
index 27bb11b0..379dcad8 100644
--- a/crates/loro-internal/src/state/movable_list_state.rs
+++ b/crates/loro-internal/src/state/movable_list_state.rs
@@ -960,6 +960,8 @@ impl ContainerState for MovableListState {
         self.list().is_empty() && self.elements().is_empty()
     }
 
+    // How we apply the diff is coupled with the [DiffMode] we used to calculate the diff.
+    // So be careful when you modify this function.
     #[instrument(skip_all)]
     fn apply_diff_and_convert(
         &mut self,
@@ -1237,6 +1239,8 @@ impl ContainerState for MovableListState {
         Diff::List(event)
     }
 
+    // How we apply the diff is coupled with the [DiffMode] we used to calculate the diff.
+    // So be careful when you modify this function.
     fn apply_diff(&mut self, diff: InternalDiff, ctx: DiffApplyContext) {
         let _ = self.apply_diff_and_convert(diff, ctx);
     }
diff --git a/crates/loro-internal/src/state/tree_state.rs b/crates/loro-internal/src/state/tree_state.rs
index a7edc34f..38b12327 100644
--- a/crates/loro-internal/src/state/tree_state.rs
+++ b/crates/loro-internal/src/state/tree_state.rs
@@ -852,6 +852,8 @@ impl ContainerState for TreeState {
         self.nodes().is_empty()
     }
 
+    // How we apply the diff is coupled with the [DiffMode] we used to calculate the diff.
+    // So be careful when you modify this function.
     fn apply_diff_and_convert(
         &mut self,
         diff: crate::event::InternalDiff,
@@ -972,6 +974,8 @@ impl ContainerState for TreeState {
         Diff::Tree(TreeDiff { diff: ans })
     }
 
+    // How we apply the diff is coupled with the [DiffMode] we used to calculate the diff.
+    // So be careful when you modify this function.
     fn apply_diff(&mut self, diff: InternalDiff, ctx: DiffApplyContext) {
         if let InternalDiff::Tree(tree) = &diff {
             let need_check = !matches!(ctx.mode, DiffMode::Checkout | DiffMode::Linear);