Network Working Group GS1 Global Office Request for Comments: XXXX Category: Informational April 2026 A Uniform Resource Name (URN) Namespace for GS1 Status of This Memo This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (2026). All Rights Reserved. Abstract This document describes a Uniform Resource Name (URN) namespace for Global Standards 1 (GS1). The namespace provides stable, unique, and persistent identifiers for GS1 identification keys, GS1 semantic artefacts, and GS1 standards and their components. The namespace includes three coordinated branches: an identification branch based on GS1 Application Identifiers (AIs), a semantic dictionary branch rooted at 'urn:gs1:gdd:', and a standards branch rooted at 'urn:gs1:std:'. This document registers the formal URN namespace 'gs1', defines its syntax, provides illustrative examples, and includes informative constraints to preserve important GS1 operational realities without overloading the core ABNF. Table of Contents 1. Introduction 2. Namespace Registration Template 3. Namespace Considerations 3.1. Relationship to RFC 5134 4. Security Considerations 5. IANA Considerations 6. References 6.1. Normative References 6.2. Informative References 7. Authors' Addresses 8. Acknowledgement Appendix A. ABNF Grammar Appendix A.1. Informative Constraints Appendix B. Regular Expressions Appendix C. Examples Appendix D. Resolver Behaviour Appendix E. OpenAPI Resolver Annex Appendix F. GS1 AI Constraint Tables Appendix G. EPC <-> GS1 Mapping 1. Introduction Global Standards 1 (GS1) is an international standards organisation that develops and maintains standards for identification, data capture, data sharing, and interoperability across supply chains, healthcare, retail, logistics, and digital ecosystems. GS1 standards include globally recognised identification keys such as the Global Trade Item Number (GTIN), Global Location Number (GLN), and Serial Shipping Container Code (SSCC). GS1 also maintains semantic artefacts and standards that define business information elements, business data types, code lists, and standard clauses used across multiple industries. This document registers the formal URN namespace 'gs1' in order to provide stable, globally unique, and persistent identifiers across these domains. The design intentionally separates three categories of identified things: o GS1 identification keys and related element strings; o GS1 semantic dictionary artefacts; o GS1 standards and their components. The document is intentionally minimalist in scope. It focuses on URN namespace registration, syntax, examples, and validation. Resolver behaviour and OpenAPI details are retained as informative appendices. 2. Namespace Registration Template This registration follows the template in RFC 8141, Appendix A. Namespace Identifier: gs1 Registration Information: Version: 1 Date: 2026-04-23 Registrant: GS1 AISBL (Global Standards 1) Avenue Louise 326 1050 Brussels Belgium URI: https://www.gs1.org/ Relevant ancillary documentation: GS1 General Specifications GS1 Application Identifiers GS1 Digital Link Standard GS1 GDD / GDSN semantic artefact construction rules GS1 Resolver Standard EPC Tag Data Standard Community considerations: The namespace is intended for use by GS1 Member Organisations, solution providers, retailers, healthcare organisations, logistics providers, regulators, standards publishers, and Semantic Web and knowledge graph communities. It provides globally unique persistent identifiers suitable for standards citation, data exchange, linked data, and machine processing. Additional information: Contact: GS1 Global Office URI: https://www.gs1.org/ Change Controller: GS1 AISBL Future revisions are controlled through GS1 governance processes and subsequent RFC publication where required. Revision information: Version 1. Initial registration. Syntactic structure: The GS1 URN namespace consists of three coordinated branches. 1. Identification branch: urn:gs1::[::...] 2. Semantic dictionary branch: urn:gs1:gdd:bie: urn:gs1:gdd:bdt: urn:gs1:gdd:cl:[:] 3. Standards branch: urn:gs1:std:[:][:] A full ABNF grammar, regular expressions, informative constraints, and illustrative examples are provided in Appendices A-G. Identifier uniqueness considerations: Identifier uniqueness is guaranteed through GS1 governance. Identification-key values are governed by GS1 allocation rules, including GS1 Company Prefix governance where applicable. Semantic artefacts and standards references are assigned under GS1-managed governance processes. Identifier persistence considerations: Identifiers are never reassigned. Deprecation, withdrawal, replacement of standards, migration of semantic infrastructure, replacement of resolver technologies, or changes to publication formats SHALL NOT invalidate an assigned GS1 URN. The identifier remains valid indefinitely, even where the identified resource becomes obsolete or superseded. Process of identifier assignment: Names are granted through GS1 processes. Depending on the branch, assignment is managed by GS1 Global Office, GS1 Member Organisations, or relevant GS1 semantic or standards governance processes. Process of identifier resolution: Resolution is optional. URN validity is independent of the existence of any resolver service. Resolver services provide a convenience mechanism for obtaining representations associated with a URN. GS1-authorised resolvers may provide authoritative representations. Example: https://resolver.gs1.org/resolve/[urn] where [urn] is the percent-encoded form of the URN. Rules for lexical equivalence: The literals 'urn', 'gs1', 'gdd', 'bie', 'bdt', 'cl' and 'std' are case-insensitive. All assigned-value components are case-sensitive unless explicitly defined otherwise by GS1 governance. No Unicode normalisation, percent-decoding, case folding, or semantic interpretation is performed when determining lexical equivalence. Lexical equivalence is determined using RFC 8141 rules combined with the namespace-specific rules defined here. Conformance with URN syntax: All GS1 URNs conform to RFC 8141 and the specific ABNF grammar in Appendix A. Validation mechanism: Syntax validation may be performed using the ABNF and regular expressions in Appendices A and B. Additional branch-specific semantic validation should be performed using the informative constraints and tables in Appendices A.1 and F. Scope: The namespace is global, covering GS1 identifiers, semantic artefacts, and standards references maintained or governed by GS1. 3. Namespace Considerations The 'gs1' namespace is required to provide stable identifiers for GS1 artefacts across registries, implementations, APIs, and documentation. It enables persistent referencing, deduplication, caching, standards citation, semantic linkage, and long-lived references in publications and knowledge graphs. The namespace design deliberately separates identifiers, semantic artefacts, and standards references because these categories have different governance and syntactic needs. This reduces ambiguity and supports simpler validation and resolution. The 'urn:gs1:gdd:' branch is preserved as a legacy-compatible semantic namespace. It identifies GS1-governed semantic artefacts independently of any particular implementation platform and remains valid even if the underlying semantic infrastructure evolves. 3.1. Relationship to RFC 5134 The GS1 URN namespace defined in this document does not replace, deprecate, or supersede the EPC URN namespace defined by RFC 5134. The two namespaces serve complementary purposes within the GS1 standards ecosystem. The EPC namespace is specifically designed to support Electronic Product Code (EPC) identification schemes and related EPC architectures. The GS1 namespace defined in this document provides a broader identifier framework covering: o GS1 identification keys and Application Identifiers; o GS1 semantic artefacts; o GS1 standards and standards components; o future GS1-governed identifier classes. The GS1 namespace therefore addresses categories of resources that are outside the scope of the EPC namespace while preserving compatibility with existing EPC deployments. Implementations MAY support mappings between EPC URNs and GS1 URNs where such mappings are defined by GS1 standards or implementation guidance. For example: urn:epc:id:sgtin:0950600.134352.9999 may be represented as: urn:gs1:01:09506000134352:21:9999 where the GTIN component is represented using Application Identifier 01 and the serial component is represented using Application Identifier 21. The existence of such mappings does not imply equivalence between the namespaces. Each namespace retains its own syntax, governance model, and resolution semantics. The GS1 namespace is intended to complement the EPC namespace by providing a consistent URN framework for the wider set of GS1-managed identifiers, semantic resources, and standards references. Additional illustrative mappings and mapping guidance are provided in Appendix G (EPC <-> GS1 Mapping). 4. Security Considerations GS1 URNs are opaque identifiers. Security considerations are therefore limited to those common to URNs in general and to the resolver infrastructure used around them. Use of non-authoritative resolvers may yield incorrect or outdated results. Resolver services should therefore use HTTPS to provide confidentiality and integrity, and clients should prefer GS1-authorised resolver services where semantic correctness matters. This registration does not itself create new security risks in identifiers. However, applications that dereference GS1 URNs should consider normal security issues for HTTP services, including spoofing, stale data, replay, and representation tampering. Intellectual property rights associated with identified artefacts are outside the scope of this registration. 5. IANA Considerations IANA is requested to register the Namespace Identifier 'gs1' in the Formal URN Namespace Registry in accordance with RFC 8141. The registration template contained in Section 2 constitutes the formal registration request. 6. References 6.1. Normative References [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", RFC 3986, January 2005. [RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", RFC 5234, January 2008. [RFC8141] Saint-Andre, P. and J. Klensin, "Uniform Resource Names (URNs)", RFC 8141, April 2017. 6.2. Informative References [GS1AI] GS1 AISBL, "GS1 Application Identifiers", current online reference dataset. [DLURI] GS1 AISBL, "GS1 Digital Link Standard: URI Syntax", Release 1.6.0, Ratified, March 2025. [RESOLVER] GS1 AISBL, "GS1-Conformant Resolver Standard", Issue 1.2.0, January 2026. [TDS] GS1 AISBL, "EPC Tag Data Standard". [GENSPECS] GS1 AISBL, "GS1 General Specifications". 7. Authors' Addresses GS1 Global Office Avenue Louise 326 1050 Brussels Belgium URI: https://www.gs1.org/ 8. Acknowledgement Funding for the RFC Editor function is currently provided by the Internet Society. Appendix A. ABNF Grammar The following ABNF grammar (RFC 5234) defines the syntax of GS1 URNs: gs1-urn = urn ":" gs1 ":" ( id-branch / gdd-branch / std-branch ) urn = %s"urn" gs1 = %s"gs1" id-branch = ai ":" value *( ":" ai ":" value ) gdd-branch = %s"gdd" ":" ( bie-branch / bdt-branch / cl-branch ) bie-branch = %s"bie" ":" bie-ref bdt-branch = %s"bdt" ":" datatype cl-branch = %s"cl" ":" codelist [ ":" code ] std-branch = %s"std" ":" std-id [ ":" version ] [ ":" clause ] ai = 2*4DIGIT value = 1*( ALPHA / DIGIT / "-" / "_" / "." ) bie-ref = 1*( ALPHA / DIGIT / "." ) datatype = 1*( ALPHA / DIGIT ) codelist = 1*( ALPHA / DIGIT ) code = 1*( ALPHA / DIGIT / "_" ) std-id = 1*( ALPHA / DIGIT / "-" ) version = 1*( DIGIT / "." ) clause = 1*DIGIT *( "." 1*DIGIT ) ALPHA = %x41-5A / %x61-7A DIGIT = %x30-39 Appendix A.1. Informative Constraints The ABNF in Appendix A intentionally defines a generic syntactic envelope. It does not encode all GS1 Application-Identifier-specific business rules because doing so would make the grammar unwieldy and difficult to maintain. Implementations should therefore apply additional semantic validation after successful syntactic parsing. General principles: * ABNF establishes syntactic admissibility. * GS1 rules establish semantic validity. * Resolver and validation services may enforce tighter constraints. Illustrative constraints: AI 01 - GTIN * numeric only * exactly 14 digits * leading zeroes preserved where required for GTIN-14 canonical form AI 00 - SSCC * numeric only * exactly 18 digits AI 414 - GLN * numeric only * exactly 13 digits AI 402 - GSIN * numeric only * exactly 17 digits AI 17 - Expiration date * numeric only * exactly 6 digits in YYMMDD form AI 10 - Batch or lot number * variable length * alphanumeric according to GS1 rules AI 21 - Serial number * variable length * alphanumeric according to GS1 rules AI 253 - GDTI * validated according to the GS1 definition for AI 253 AI 401 - GINC * validated according to the GS1 definition for AI 401 AI 8003 - GRAI * validated according to the GS1 definition for AI 8003 AI 8004 - GIAI * may be alphanumeric * validated according to the GS1 definition for AI 8004 Canonical lexical form should be preserved where it exists. In particular, fixed-length numeric identifiers should retain leading zeroes and AI codes should be represented in their standard numeric form. Appendix B. Regular Expressions Identification branch: ^[Uu][Rr][Nn]:[Gg][Ss]1:[0-9]{2,4}:[A-Za-z0-9._-]+(:[0-9]{2,4}:[A-Za-z0-9._-]+)*$ Semantic dictionary branch: ^[Uu][Rr][Nn]:[Gg][Ss]1:[Gg][Dd][Dd]:(?:[Bb][Ii][Ee]:[A-Za-z0-9.]+|[Bb][Dd][Tt]:[A-Za-z0-9]+|[Cc][Ll]:[A-Za-z0-9]+(?::[A-Za-z0-9_]+)?)$ Standards branch: ^[Uu][Rr][Nn]:[Gg][Ss]1:[Ss][Tt][Dd]:[A-Za-z0-9-]+(?::[0-9.]+)?(?::[0-9]+(?:\.[0-9]+)*)?$ Appendix C. Examples The following are non-normative examples of GS1 URNs. Identification branch: urn:gs1:01:09506000134352 urn:gs1:00:195060001343521234 urn:gs1:414:9506001343521 urn:gs1:402:12345678901234567 urn:gs1:8004:ABC123XYZ urn:gs1:01:09506000134352:10:ABC123:21:9999 urn:gs1:01:09506000134352:17:250101 Semantic dictionary branch: urn:gs1:gdd:bie:TradeItem urn:gs1:gdd:bie:TradeItem.netContent urn:gs1:gdd:bie:TradeItem.brandOwner.PartyInRole urn:gs1:gdd:bie:TradeItem.generalization.PartyInRole urn:gs1:gdd:bdt:MeasurementType urn:gs1:gdd:cl:CountryCode urn:gs1:gdd:cl:CountryCode:BE Standards branch: urn:gs1:std:genspec urn:gs1:std:genspec:24.0 urn:gs1:std:genspec:24.0:5.3.1 urn:gs1:std:epcis:2.0:4.2 urn:gs1:std:dl:1.6:7.1 Appendix D. Resolver Behaviour Resolver behaviour is informative and not required for URN validity. GS1-authorised resolvers should support representation negotiation while keeping URNs themselves stable and version-independent where appropriate. Recommended representations: * text/html * application/pdf * application/xml * text/markdown * application/ld+json For standards references, clause-level resolution should return the addressed standard or clause in the requested representation when available. For semantic artefacts, version-specific representations may be negotiated using Accept parameters or query parameters while keeping the URN itself version-independent. Appendix E. OpenAPI Resolver Annex openapi: 3.1.0 info: title: GS1 URN Resolver API version: 1.0.0 paths: /resolve/{urn}: get: summary: Resolve a GS1 URN parameters: - name: urn in: path required: true schema: type: string - name: Accept in: header required: false schema: type: string - name: version in: query required: false schema: type: string responses: '200': description: Resolved resource '400': description: Invalid URN '404': description: Unknown URN Appendix F. GS1 AI Constraint Tables The following table is informative. +------+----------------------+----------------------+----------------------+ | AI | Meaning | Character set | Length / form | +------+----------------------+----------------------+----------------------+ | 00 | SSCC | numeric | exactly 18 digits | | 01 | GTIN | numeric | exactly 14 digits | | 10 | batch or lot | GS1-defined alpha | variable | | 17 | expiration date | numeric | YYMMDD | | 21 | serial number | GS1-defined alpha | variable | | 253 | GDTI | GS1-defined | per GS1 definition | | 401 | GINC | GS1-defined | per GS1 definition | | 402 | GSIN | numeric | exactly 17 digits | | 414 | GLN | numeric | exactly 13 digits | | 8003 | GRAI | GS1-defined | per GS1 definition | | 8004 | GIAI | GS1-defined alpha | per GS1 definition | +------+----------------------+----------------------+----------------------+ Appendix G. EPC <-> GS1 Mapping This appendix is informative and is provided to illustrate interoperability between the namespaces described in Section 3.1. The mappings shown herein do not establish semantic equivalence between the EPC and GS1 namespaces and do not alter the independent governance or syntax rules applicable to either namespace. The following is a non-normative example of mapping between an EPC identifier and a GS1 URN. urn:epc:id:sgtin:0950600.134352.9999 -> urn:gs1:01:09506000134352:21:9999 Informative mapping rule: 1. Concatenate company prefix and item reference to form GTIN-14. 2. Preserve required numeric padding. 3. Map EPC serial component to AI 21. 4. Reverse mapping is possible where components are present and unambiguous.