| Clue | Source | Date |
|---|---|---|
| Cereal proofs-of-purchase, often | Thomas Joseph | 16 Sep 2022 |
| *Cardboard clippings for schools | Wall Street Journal | 12 May 2020 |
| Some proofs of purchase | ||
| Some proofs-of-purchase | ||
| Some proofs-of-purchase | ||
| "The Letter" group, with "the" | ||
| "The Letter" group | ||
| Some proof-of-purchases | ||
| They're redeemable for premiums. |