ISO 8583 Definition.
The long-standing standard for card payment messages: message types (0100 authorization, 0110 response, 0400 reversal, and so on) and numbered fields such as 2 (PAN), 4 (amount), 11 (STAN), 37 (RRN), and 39 (response code). Every scheme and every domestic protocol, including CB2A, derives its own dialect from it. It remains the backbone of card networks, despite the rise of ISO 20022 and APIs.
See also
Where this term appears
GuideThe four-party modelGuideCard issuing: building and running a programGuideA global history of paymentsGuideTaking payments by phoneGuidePayment orchestrationGuidePayment declines and how to handle themGuideThe payment state machineGuideNational switches and clearing housesGuidePOS terminals and in-store payments around the worldGuideIn-store paymentsGuideAuthorizationGuideClearing and settlement