A Note on Credit Card Security
In the interest of protecting your credit card information, we ask that you provide either AVS, CVV2 or both types of credit card verification information.
AVS information is the address associated with the credit card. In most cases this is your billing address with AVS1 being the street address and AVS2 being the zipcode.
CVV2 is another number that's printed on the back of Visa and Mastercard and on the front of American Express cards. Here's an example of some CVV2 numbers.