Appendix B - Effective Keyword Searches > Searching for credit card numbers

To search for credit card numbers using the creditcard operator, and any numerical sequence that credit-card issuers use to determine card validity, regardless of spacing and punctuation, is recognized. For example, the following sequences will all return text following the number specified:

creditcard(1234 5678 1234 5678)

creditcard(1234-5678-1234-5678)

creditcard(1234567812345678)

Occasionally, other numbers may also be returned by this operator.