3 ms·
A credit card number already has a check digit. If you could make people memorize a few more digits than the telephone number that they'd like to call, you have
by JoachimSchipper 15y ago
A credit card number already has a check digit. If you could make people memorize a few more digits than the telephone number that they'd like to call, you have your error correction.
(Of course, this is highly domain-specific and not very convenient. But it does seem possible.)