Standards reference

Reference of standards, specifications, and frameworks cited in the OTL protocol specification and flow explorer, with URLs and licensing terms for informational purposes. Implementors are responsible for independently assessing and complying with the terms applicable to any third-party standard they implement.

1. Financial Messaging & Payment
StandardFull NameBodyURLLicense / Access
ISO 20022Universal financial industry message schemeISO TC68iso20022.orgPaywalled (ISO); schema/message definitions freely downloadable via iso20022.org
ISO 18245Merchant Category Codes (MCC)ISOiso.orgPaywalled (ISO); MCC tables widely available openly
ISO 4217Currency CodesISOiso.orgPaywalled; codes themselves freely usable — SIX Group publishes free tables
2. Regulatory & Compliance
StandardFull NameBodyURLLicense / Access
FATF Travel RuleRecommendation 16 — Virtual AssetsFATFfatf-gafi.orgFree; public guidance
IVMS101Inter-VASP Messaging Standard 101GBBC Digital Finance / OpenVASP / VASPnetintervasp.orgFree; open standard; data model standard text is CC BY-ND 4.0
ISO 17442Legal Entity Identifier (LEI)ISO / GLEIFiso.orgPaywalled (ISO spec); LEI data is CC0 via GLEIF
GLEIF APIGlobal LEI Foundation — LEI data & registryGLEIFgleif.orgCC0 (Public Domain) — freely available, 60 req/min
3. Digital Identity — DIDs & Credentials
StandardFull NameBodyURLLicense / Access
W3C DID Core 1.0Decentralized IdentifiersW3Cw3.orgW3C Software and Document License
did:webvhWeb Verifiable Hosting DID MethodDIF / W3C CCGidentity.foundationW3C Patent Policy (2004)
W3C VC Data Model v2.0Verifiable Credentials Data ModelW3Cw3.orgW3C Software and Document License
W3C Data Integrity / eddsa-jcs-2022EdDSA Data Integrity CryptosuiteW3Cw3.orgW3C Software and Document License
Ed25519 / X25519 Key SuitesEd25519VerificationKey2020 / X25519KeyAgreementKey2020W3C CCGw3id.orgW3C Community Group Report License
RFC 9901SD-JWT — Selective Disclosure for JWTsIETFdatatracker.ietf.orgIETF Trust License
draft-ietf-oauth-sd-jwt-vcSD-JWT Verifiable Credentials ProfileIETFdatatracker.ietf.orgIETF Trust License
OID4VCIOpenID for Verifiable Credential IssuanceOpenID Foundationopenid.netOpenID Foundation IPR Policy
MultibaseMultibase encoding (base58btc / z-prefix)W3C CCGw3c-ccg.github.ioW3C CLA (spec) / Apache 2.0 (implementations)
4. Cryptographic Suites & Encodings
StandardFull NameBodyURLLicense / Access
RFC 7515JSON Web Signature (JWS)IETFdatatracker.ietf.orgIETF Trust License
RFC 7516JSON Web Encryption (JWE)IETFdatatracker.ietf.orgIETF Trust License
RFC 7517JSON Web Key (JWK)IETFdatatracker.ietf.orgIETF Trust License
RFC 7519JSON Web Token (JWT)IETFdatatracker.ietf.orgIETF Trust License
RFC 8785JSON Canonicalization Scheme (JCS)IETFdatatracker.ietf.orgIETF Trust License
5. Messaging & Transport
StandardFull NameBodyURLLicense / Access
DIDComm Messaging v2DIDComm v2DIFidentity.foundationW3C Software and Document License
RFC 6749OAuth 2.0 Authorization FrameworkIETFdatatracker.ietf.orgIETF Trust License
RFC 7595Guidelines for URI Scheme RegistrationIETFdatatracker.ietf.orgIETF Trust License
JSON-LD 1.1JSON-LD (Linked Data)W3Cw3.orgW3C Software and Document License
6. Asset Identification
StandardFull NameBodyURLLicense / Access
ISO 24165 / DTIDigital Token IdentifiersISO / DTIFdtif.orgISO spec paywalled; DTI codes and reference data freely available via dtif.org
CAIP-2Blockchain ID SpecificationCASAchainagnostic.orgCC0 (Public Domain)
CAIP-19Asset Type and Asset ID SpecificationCASAchainagnostic.orgCC0 (Public Domain)
CAIP-358Universal Payment Request Method (wallet_pay)CASAchainagnostic.orgCC0 (Public Domain) — Draft
7. Blockchain / EVM Standards
StandardFull NameBodyURLLicense / Access
EIP-1193Ethereum Provider JavaScript APIEthereum Foundationeips.ethereum.orgCC0 (Public Domain)
EIP-191Signed Data Standard (personal_sign)Ethereum Foundationeips.ethereum.orgCC0 (Public Domain)
ERC-20 / EIP-20Ethereum Token StandardEthereum Foundationeips.ethereum.orgCC0 (Public Domain)
SPL-TokenSolana Program Library Token StandardSolana Labsspl.solana.comApache 2.0
8. ISO Utility Standards
StandardFull NameBodyURLLicense / Access
ISO 8601Date and Time RepresentationISOiso.orgPaywalled
ISO 3166-1Country Codes (alpha-2)ISOiso.orgFree — ISO allows free use; data tables at iso.org
ISO/IEC 18004QR Code (2D Barcode) SpecificationISO/IEC JTC1iso.orgPaywalled