Empty list example

docs/sql/functions/nested.md

@@ -344,8 +344,14 @@ SELECT
 [[1, 2], [3, 4], [5, 6], [7, 8]] 
 ```
 
-The behavior of the flatten function also has specific behavior when handling `NULL` values:
+In general, the input to the flatten function should be a list of lists (not a single level list). 
+However, the behavior of the flatten function has specific behavior when handling empty lists and `NULL` values.
 ```sql
+-- If the input list is empty, return an empty list
+SELECT flatten([]);
+----
+[]
+
 -- If the entire input to flatten is NULL, return NULL
 SELECT flatten(NULL);
 ----