title: Discretionary data from magnetic strip credit card, how to parse?
body: <p>according to wiki, the Discretionary data — </p>
  
  <blockquote>
    <p>may include Pin Verification Key Indicator (PVKI, 1 character), PIN
    Verification Value (PVV, 4 characters), Card Verification Value or
    Card Verification Code (CVV or CVC, 3 characters)</p>
  </blockquote>
  
  <p>This means that it's not guaranteed that I would always be able to get the CVC, which is a problem for me. I was able to use an existing implementation to parse my credit card stripe and got a bunch of numbers for the discrepdata. I'm not sure exactly how to interpret exactly. Since its more than 8 chars and does not match my cvc, or pin number. </p>
  
  <p>It looks like(numbers are random, but the padded 0's are the same):
  0000031200100</p>
  
  <p>What does this mean?</p>