diff --git a/LogicalTypes.md b/LogicalTypes.md
index b8d19cde..8b2a65ad 100644
--- a/LogicalTypes.md
+++ b/LogicalTypes.md
@@ -681,6 +681,11 @@ optional group array_of_arrays (LIST) {
 
 #### Backward-compatibility rules
 
+Modern writers should always produce the 3-level LIST structure shown above.
+However, historically data files have been produced that use different structures to
+represent list-like data, and readers may include compatibility measures to interpret
+them as intended.
+
 ##### 3-level structure with different field names
 
 It is required that the repeated group of elements is named `list` and that