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DRAFT⚠OIML SMART pilot programme · internal use only · all documents and specifications are drafts and may change without notice
OIML SMART

URN Specification

OIML SMART assigns a Uniform Resource Name (URN) in the urn:oiml namespace to every publication, SMART model element, certificate, and organizational body it identifies.

OIML SMART assigns a Uniform Resource Name (URN) as the persistent identifier of every entity it publishes: OIML publications and their clauses, the elements of a SMART model, certificates of conformity, and organizational bodies. URNs are location-independent, so they survive repository moves, redesigns, and changes to the publishing infrastructure, and a URN can be resolved through different services over time.

The namespace

The OIML URN namespace is urn:oiml:. A sub-namespace identifies the entity class:

Sub-namespace Identifies Example
pub A publication, a part, a clause, or a vocabulary term urn:oiml:pub:r:60-1:2021#clause-5.4
pub … :req: An element of a SMART model urn:oiml:pub:r:60:2021:req:/metrological/mpe
cs:cert An OIML-CS certificate urn:oiml:cs:cert:r:60:2021:a:de1:26.01
group An organizational body urn:oiml:group:tc:3
bulletin An OIML Bulletin issue urn:oiml:bulletin:2026-01

All values are lower-case, empty fields between colons are omitted, and multi-part publications embed the part number in the document-number field (60-1 for OIML R 60-1).

Resolution

A URN transforms into a valid HTTP URI by replacing the namespace prefix with the web domain of the resolving service and mapping the resource class to the URL path. Publication references resolve against the OIML web site, and the elements of a SMART model resolve against the SMART platform.

urn:oiml:pub:r:60:2021
  → https://www.oiml.org/pub/r/60/2021

urn:oiml:pub:r:60:2021:req:/metrological/mpe
  → https://platform.oimlsmart.org/pub/r/60/2021/req/metrological/mpe

urn:oiml:cs:cert:r:60:2021:a:de1:26.01
  → https://www.oiml.org/cs/cert/r/60/2021/a/de1/26.01

urn:oiml:group:tc:3
  → https://www.oiml.org/group/tc/3

Cross-references

Within a SMART Recommendation every cross-reference is encoded as a URN, and the build validates that each referenced URN resolves to a declared entity, so a dangling reference fails the build. Human-readable citations derive from URNs: urn:oiml:pub:r:60-1:2021 cites as OIML R 60-1:2021, and urn:oiml:pub:r:60-1:2021#clause-5.4 cites as R 60-1, 5.4.

Compatibility

The OIML URN scheme is designed to be compatible with the IEC-ISO SMART identifier system where applicable, so that a cross-organization reference is unambiguous.