[urn] Submission URN:SDMX

Network Working Group                                          SDMx Sponsors
Request for Comments:                                      
Category: Informational                                        
                                                              August 13th, 2026

           A Uniform Resource Name (URN) Namespace
        for The Standard for Statistical Data and Metadata (SDMx)

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 
   'The Standard for Statistical Data and Metadata' (SDMx). The namespace provides 
   stable, unique identifiers for SDMx artefacts such as data structures, 
   code lists, concept schemes, and related structural metadata.

Table of Contents

   1. Introduction
   2. Namespace Registration Template
   3. Namespace Considerations
   4. Security Considerations
   5. IANA Considerations
   6. References
      6.1. Normative References
   7. Authors' Addresses
   8. Acknowledgement
   Appendix A. ABNF Grammar
   Appendix B. Regular Expressions
   Appendix C. Examples

1. Introduction

   SDMx (The Standard for Statistical Data and Metadata) is an international 
   initiative sponsored by the Bank for International Settlements (BIS), 
   the European Central Bank (ECB), Eurostat, the International Monetary 
   Fund (IMF), the Organisation for Economic Co-operation and Development 
   (OECD), the United Nations Statistics Division (UNSD), the International 
   Labour Organization (ILO), and the World Bank.

   SDMx defines an ISO standard (ISO 17369) for describing statistical data 
   and metadata, standardizing their exchange, and improving efficiency of 
   sharing across organizations. Artefacts include data structures, code 
   lists, concept schemes, metadata structures, and validation rules.

   This document registers the formal URN namespace "sdmx", to ensure 
   stable, unique, and persistent identification of SDMx artefacts.

2. Namespace Registration Template

   This registration follows the template in RFC 8141, Appendix A.

   Namespace ID:
      sdmx

   Registration Information:
      Version: 1
      Date: 2026-08-13

   Declared registrant of the namespace:
      SDMx Sponsors
      c/o SDMx Secretariat
      Email: [email protected]
      URI: https://sdmx.org/

   Syntactic structure:
      The general form of an SDMx URN is:

         urn:sdmx:<class-path>=<agency-id>:<object-id>(<version>)[.<item-seq>]

      A full ABNF grammar, regular expressions, and illustrative examples 
      are provided in Appendices A-C.

   Identifier uniqueness considerations:
      Identifiers are assigned by SDMx Sponsors and authorized agencies. 
      The governance process guarantees uniqueness across organizations 
      through coordinated registries.

   Identifier persistence considerations:
      Names are never reassigned. Once issued, an SDMx URN is valid 
      indefinitely, supporting long-term archival use.

   Process of identifier assignment:
      Names are granted via SDMx registration procedures, including the 
      SDMx Global Registry and designated national or international 
      organizations.

   Process of identifier resolution:
      The official resolver is:
         https://urn.sdmx.io/resolve/[urn]
      where [urn] is the percent-encoded form of the URN. Alternative 
      resolvers may exist, but only the official resolver is authoritative.

   Rules for lexical equivalence:
      Equivalence is defined as binary identity except that the "urn" and 
      "sdmx" literals and agency-id labels are compared case-insensitively. 
      No other normalizations are performed.

   Conformance with URN syntax:
      All SDMx URNs comply with the syntax in RFC 8141 and the specific 
      ABNF grammar in Appendix A.

   Validation mechanism:
      Syntax validation may be performed using the ABNF and regexes in 
      Appendices A and B. Semantic validation is performed by SDMx tools 
      and registries.

   Scope:
      The namespace is global, covering all SDMx artefacts and nested 
      components maintained by SDMx Sponsors, international organizations, 
      agencies and national statistical offices.

3. Namespace Considerations

   The "sdmx" namespace is required to provide stable identifiers for SDMx 
   artefacts across registries and implementations. It enables referencing, 
   deduplication, caching, and long-lived citation in publications and APIs.

4. Security Considerations

   SDMx URNs are opaque identifiers. Security considerations are limited to 
   those common to URNs in general. Use of non-authoritative resolvers may 
   yield incorrect results. The official resolver requires HTTPS to ensure 
   confidentiality and integrity.

   Intellectual property rights associated with artefacts are outside the 
   scope of this registration.

5. IANA Considerations

   IANA is requested to register the formal URN namespace "sdmx" in the 
   registry of URN Namespaces, following RFC 8141.

6. References

6.1. Normative References

   [RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax 
             Specifications: ABNF", STD 68, RFC 5234, 
             DOI 10.17487/RFC5234, January 2008.

   [RFC8141] Saint-Andre, P. and J. Klensin, "Uniform Resource Names (URNs)", 
             RFC 8141, DOI 10.17487/RFC8141, April 2017.

   [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, 
             "Uniform Resource Identifier (URI): Generic Syntax", 
             RFC 3986, January 2005.

   [SDMx]    SDMx Sponsors, "SDMx Technical Specifications, Version 3.1, 
             Section 6", May 2025, 
             https://sdmx.org/wp-content/uploads/SDMX_3-1-0_SECTION_6_FINAL.pdf

7. Authors' Addresses

   Tom Roberts
   smartXdata Technologies Inc.
   1000 Brickell Avenue
   Suite #715 PMB 670
   Miami, Florida 33131
   United States of America
   Email: [email protected]
   URI: https://smartxdata.com

8. Acknowledgement

   Funding for the RFC Editor function is currently provided by the 
   IETF Administration LLC (IETF LLC).

Appendix A. ABNF Grammar

   The following ABNF grammar (RFC 5234) defines the syntax of SDMx URNs:

      sdmx-urn           = urn ":" sdmx ":" class-path "=" agency-id ":" object-id
                            "(" version ")" [ "." item-seq ]

      urn                = "urn"
      sdmx               = "sdmx"

      class-path         = class-label *( "." class-label )
      class-label        = 1*( ALPHA / DIGIT / "_" )

      agency-id          = agency-label *( "." agency-label )
      agency-label       = ALPHA *( ALPHA / DIGIT / "_" / "-" )

      object-id          = 1*id-char

      version            = version-core [ pre-release ]
      version-core       = 1*DIGIT "." 1*DIGIT [ "." 1*DIGIT ]
      pre-release        = "-" pre-id *( "." pre-id )
      pre-id             = 1*( ALPHA / DIGIT / "-" )

      item-seq           = item-id *( "." item-id )
      item-id            = 1*id-char

      id-char            = ALPHA / DIGIT / "-" / "_" / "@" / "$"

      ALPHA              = %x41-5A / %x61-7A
      DIGIT              = %x30-39

   Notes:
      o "urn" and "sdmx" literals and agency-id labels are compared
        case-insensitively; all other components are case-sensitive.

Appendix B. Regular Expressions

   The following regexes (PCRE/XML Schema style) can be used for validation:

   Full URN (case-insensitive literals "urn" and "sdmx"):

      ^[Uu][Rr][Nn]:[Ss][Dd][Mm][Xx]:
        [A-Za-z0-9_]+(\.[A-Za-z0-9_]+)*
        =[A-Za-z][A-Za-z0-9_-]*(\.[A-Za-z][A-Za-z0-9_-]*)*
        :[A-Za-z0-9_@$-]+
        \([0-9]+\.[0-9]+(\.[0-9]+)?(-[A-Za-z0-9-]+(\.[A-Za-z0-9-]+)*)?\)
        (\.[A-Za-z0-9_@$-]+(\.[A-Za-z0-9_@$-]+)*)?$

   Components:

      <class-path>   ::= [A-Za-z0-9_]+(\.[A-Za-z0-9_]+)*
      <agency-id>    ::= [A-Za-z][A-Za-z0-9_-]*(\.[A-Za-z][A-Za-z0-9_-]*)*
      <object-id>    ::= [A-Za-z0-9_@$-]+
      <item-id>      ::= [A-Za-z0-9_@$-]+
      <version>      ::= [0-9]+\.[0-9]+(\.[0-9]+)?(-[A-Za-z0-9-]+(\.[A-Za-z0-9-]+)*)?

Appendix C. Examples

   The following are non-normative examples of SDMx URNs:

      urn:sdmx:org.sdmx.infomodel.codelist.Codelist=SDMX:CL_FREQ(2.0)

      urn:sdmx:org.sdmx.infomodel.codelist.Code=SDMX:CL_FREQ(2.0).A
      
      urn:sdmx:org.sdmx.infomodel.conceptscheme.ConceptScheme=IMF.STA.DS:CS_DQAF_BOP_IIP_NEW(1.0.0)

      urn:sdmx:org.sdmx.infomodel.datastructure.DataStructure=ESTAT:CPI(1.1)

      urn:sdmx:org.sdmx.infomodel.categoryscheme.Category=SDMX:STAT_SUBJECT_MATTER(1.0).DEMO_SOCIAL_STAT