match accuracy in Data Loss Provention

[px091]

Can someone please explain what is the meaning of match accuracy Min and Max in DLP in office 365?

when I create a rule for credit card number, it assign the following value for Match Accuracy

    min 85, max 100

what are those numbers mean? how the default value set to 80 and 100?

Thanks in advance,

Peter 

[#2 · Accepted solution]

It's basically an indicator of how good a match would be. For example a 16 digit number that passes the Luhn check will have 65% accuracy, while if additional evidence is found around the number (expiration date) will have improved accuracy. Read here for more details: 

https://docs.microsoft.com/en-us/microsoft-365/compliance/data-loss-prevention-policies?view=o365-wo...