Card Verification Value 
Card Verification Value
Definition
The
card verification value (CVV) is a number, additional to the card number, which acts as a security feature in payment card processing.Use
When you create a payment card transaction, you enter this value on the Payment form tab page in the CVV field. Because, for legal reasons, CVVs cannot be saved in business partner master data, you must enter them manually. In other words, you cannot use either Possible entries help or 
(Default card) to enter CVVs.
The system then sends the CVV, along with other card data, to the clearing house during authorization. The clearing house checks the CVV and sends the results back to the system, which displays them on the Payment Form tab.
The system saves the CVV in the transaction, so that, if you carry out additional authorizations later, you do not need to enter the CVV again.
You can determine in Customizing how the system responds to the results of the CVV check. For example, you could set it to issue a warning if the CVV is not correct, or to block further processing of the transaction.
Customer Relationship Management ® Basic Functions ® Payment Card Processing ® Settings For Transactions ® Define Checking Group.
Customer Relationship Management ® Basic Functions ® System Modifications ® Payment Cards ® Structure for Communication with the Clearing House.