Each card issuer is required to maintain an ACS used to support cardholder authentication. The standard was created to increase controls around cardholder data to reduce credit card fraud. The minimum cardholder account information needed to complete a transaction is present on both tracks. Some issuers discourage redemption by forcing the cardholder to call customer service for rewards. This provides some verification that the card was delivered to the actual cardholder. Mastercard uses AAV (Accountholder Authentication Value) and Visa uses CAVV (Cardholder Authentication Verification Value). Other rules govern what creates an enforceable proof of authorization by the cardholder. The cardholder may not discover fraudulent use until receiving a statement. The AID is printed on all EMV cardholder receipts. However, Mastercard denied this, stating that "cardholder account data has not been placed at risk". Visa requires that this markup be disclosed to the cardholder. There are many cardholder verification methods (CVMs) supported in EMV. The main benefit to the cardholder is convenience. The registered multi-ride ticket is limited to personal use by the registered cardholder. MasterCard again teamed up with Usher in 2015 to surprise one cardholder.