title: Calculate CVV from Credit card tracks?
body: <p>Can I calculate the CVV from the 3 credit card track data?
  When I scan a card, there is no CVV, just the number, name and service numbers that don't relate to anything else.</p>
  
  <p>Ref: <a href="https://stackoverflow.com/questions/2121881/parse-credit-card-input-from-magnetic-stripe">Parse Credit Card input from Magnetic Stripe</a></p>