| Clue | Source | Date |
|---|---|---|
| Santa's is H0H 0H0, in Canada | New York Times | 22 Oct 2022 |
| In Canada, Santa’s is H0H 0H0 | Wall Street Journal | 21 May 2022 |
| A communications innovation first used in the UK in Norwich (1959) and Croydon | The Times Specialist Sunday | 07 Jan 2018 |
| Feature of some letters | Newsday | 26 Aug 2016 |
| M5V 2T6, for Toronto's CN Tower | Wall Street Journal | 13 Mar 2015 |
| M5V 2T6, for Toronto's CN Tower | ||
| Letter-routing number | ||
| ZIP |