| Clue | Source | Date |
|---|---|---|
| Spots with no bars | Thomas Joseph | 25 Jul 2026 |
| Spots with no bars | Thomas Joseph | 29 Jun 2024 |
| Spots with no reception | Thomas Joseph | 12 Feb 2022 |
| Spots with no bars | Thomas Joseph | 28 Mar 2020 |
| Areas with no bars? | Wall Street Journal | 19 Nov 2015 |
| Areas with no bars? |