diff --git a/README.md b/README.md
index 6aa96d8..2406247 100644
--- a/README.md
+++ b/README.md
@@ -61,6 +61,7 @@ user_details
 - [] automatically add regular planned trip
 - [] same day+time: aggregate stats (x people, of which y cox and z rower)
 - [] Lock trip; noone can register anymore
+- [] on delete cascade doesn't work; e.g. created planned_event/trip + delete it -> trip_details entry still there!