Rulebooks, procedures, and implementation guidelines for participation and payment flows across schemes, networks, and rails.

Specifications for interoperable acceptance across terminals, acquiring hosts, contactless devices, QR, and remote checkout.

Standards securing data, software, cryptographic keys, credentials, devices, and authentication in physical and digital payments.

Standards for issuer, account, institution, merchant, country, currency, and legal entity codes and identifiers.

Standards and profiles defining payment message structure, semantics, and exchange between institutions and infrastructure.

Security profiles, API frameworks, and local standards for permissioned data sharing, account access, and payment initiation.