| Clue | Source | Date |
|---|---|---|
| Spy rings? | LA Times Daily | 24 Jun 2023 |
| Tweet from those on the golf course giving some insights into how those in The Houses secretly see things | Irish Times Crosaire | 22 Oct 2020 |
| Features of most hotel doors | New York Times | 04 May 2020 |
| Door features | Thomas Joseph | 07 Apr 2018 |
| Openings for furtive glances | The Washington Post | 06 Jan 2017 |
| Door features | ||
| Spying apertures | ||
| Spy rings? | ||
| Apartment security devices | ||
| Openings for spies | ||
| Viewpoints? |