Record that a specific shop_domain + code (coupon) pair is wrong in one of four fixed, documented ways (invalid | mismatch | item_restricted | min_order_missing — see reasons enum; no free text anywhere). This is a write: it appends one new report row and NEVER changes the delivered coupon directly — it never deletes or overwrites data, and it does not itself decide anything. Subject to per-source dedup it only queues a re-check (RecheckQueueEntry); only a separate Pruefurteil process may later change what list_coupons returns. Reply is a status text ('wird gemeldet, Pruefung laeuft'), never a verdict.