| Monikko | exceptions that prove rules |
| Monikko | exceptions that prove the rule |
The rare occurrence of a counterexample to a rule, used to demonstrate that the rule exists.
A Controlled Parking Zone sign used in the United Kingdom, prohibiting parking during certain times. If a driver is unsure about whether parking is allowed in a certain location, such a sign helps demonstrate the existence of a general rule that parking is allowed outside the times listed.