Re:NULL license plate not such a bright idea
by dredmorbius on Tuesday August 13, 2019 @09:25AM
(#20685562)
Or an arbitrary number of characters. If you know the additional six alphanumeric characters added, that's another 14 million combinations to test.
Or 2FA, or ....
For bank cards with fixed lengths, increment/decrement the nth character, swap two characters, or do a circular shift.