| Clue | Source | Date |
|---|---|---|
| A digit representing the contents of a piece of computer data, used to verify its integrity (8) | ||
| Validation problem with bill | The Telegraph Toughie | 02 Nov 2023 |
| Help to totter Crown, we hear? | The Telegraph Toughie | 31 May 2019 |
| Help to find errors in score after hearing how Bohemian Rhapsody sounds? | The Times Cryptic | 10 Jul 2017 |