| Clue | Source | Date |
|---|---|---|
| Mail conveniences | Universal | 25 Oct 2018 |
| Mail conveniences | ||
| Mail conveniences ... or a hint to eight squares in this puzzle | New York Times | 21 Aug 2014 |
| Mail conveniences ... or a hint to eight squares in this puzzle | ||
| Mail holders | ||
| They're usually numbered | ||
| They're usually numbered |