ECThe Asset Description Metadata Schema (ADMS) is a vocabulary for describing semantic assets -- reusable metadata specifications such as XML schemas, data models, code lists, taxonomies, and vocabularies. Now in its 2.0 release, ADMS provides a structured way for organisations, particularly in the European public sector, to discover, evaluate, and share interoperability assets across institutional and national boundaries.
Background
ADMS was first developed and published by the European Commission ISA Programme in April 2012, driven by the need to improve the discoverability and reuse of semantic interoperability assets across EU Member States. Contributors included representatives of Member States, operators of national repositories, standardisation bodies, and independent experts.
The vocabulary was subsequently refined by the W3C Government Linked Data Working Group, which published ADMS as a W3C Working Group Note on 1 August 2013. That version positioned ADMS as a profile of DCAT, inheriting structural patterns from the data catalogue vocabulary.
After a decade of implementation experience -- particularly on the European Commission's JoinUp platform -- the Interoperable Europe initiative of the European Commission took up active maintenance. The 2.0 release, published on 1 February 2024 as a SEMIC Recommendation, decouples ADMS from DCAT to give both vocabularies independent lifecycles while preserving backward compatibility.
Purpose and Scope
ADMS focuses on the nature of semantic assets rather than their organisation in catalogues. It addresses a specific use case: someone searching for a reusable metadata artifact (a schema, a code list, a vocabulary) has different needs than someone searching for a dataset. ADMS captures properties relevant to these artifacts, including versioning relationships, interoperability levels, representation techniques, and distribution formats.
While ADMS 2.0 is formally independent of DCAT, the specification provides guidance on how to construct a DCAT profile using ADMS terms when cataloguing semantic assets is the goal.
Key Classes and Properties
ADMS 2.0 defines four classes and thirteen properties:
Classes
| Class | URI | Description |
|---|---|---|
| Asset | adms:Asset | An abstract entity reflecting the intellectual content of a semantic asset |
| Asset Distribution | adms:AssetDistribution | A particular physical embodiment of an Asset |
| Asset Repository | adms:AssetRepository | A system providing storage, maintenance, and search of Asset descriptions |
| Identifier | adms:Identifier | An identifier in a particular context, based on UN/CEFACT |
Properties
| Property | Domain | Range |
|---|---|---|
| identifier | rdfs:Resource | adms:Identifier |
| includedAsset | adms:Asset | adms:Asset |
| interoperabilityLevel | adms:Asset | skos:Concept |
| last | rdfs:Resource | rdfs:Resource |
| next | rdfs:Resource | rdfs:Resource |
| prev | rdfs:Resource | rdfs:Resource |
| representationTechnique | rdfs:Resource | skos:Concept |
| sample | rdfs:Resource | rdfs:Resource |
| schemaAgency | adms:Identifier | rdfs:Literal |
| status | rdfs:Resource | skos:Concept |
| supportedSchema | rdfs:Resource | adms:Asset |
| translation | rdfs:Resource | rdfs:Resource |
| versionNotes | rdfs:Resource | rdfs:Literal |
Serializations and Technical Formats
ADMS is available in three RDF serializations published under the W3C namespace:
- Turtle: http://www.w3.org/ns/adms.ttl
- N-Triples: https://www.w3.org/ns/adms.nt
- RDF/XML: https://www.w3.org/ns/adms.rdf
The canonical namespace URI is http://www.w3.org/ns/adms#.
Governance and Maintenance
ADMS is now maintained by the European Commission through the SEMIC (Semantic Interoperability Community) initiative under the Interoperable Europe programme. W3C and the European Commission collaborate on active maintenance. The vocabulary is published under the CC-BY 4.0 license. Development is managed through a public GitHub repository, and community input is collected through issue tracking and periodic webinars.
Notable Implementations
ADMS has been widely deployed in the European interoperability ecosystem. The adms:identifier property in particular has been adopted beyond its original scope into vocabularies such as DCAT-AP and the SEMIC Core Vocabularies. The European Commission's JoinUp platform served as the primary implementation context for ADMS, enabling EU institutions and Member States to share and discover semantic assets. National interoperability frameworks across Europe have adopted ADMS for cataloguing their metadata specifications and code lists.
Related Standards
- DCAT -- the data catalogue vocabulary from which ADMS was originally derived as a profile; ADMS 2.0 decouples this dependency while maintaining alignment