DCMIDCMI Metadata Terms is the authoritative, consolidated specification of every metadata term maintained by the Dublin Core Metadata Initiative. Where the original Dublin Core Metadata Element Set defined fifteen broadly applicable properties, DCMI Metadata Terms expands on that foundation with additional properties bearing formal RDF domains and ranges, a set of classes for typing values, vocabulary and syntax encoding schemes, and utility terms for vocabulary description. It is the primary vocabulary that DCMI recommends for new implementations and serves as the basis for ISO 15836-2:2019.
Background
The Dublin Core Metadata Element Set emerged from a 1995 workshop in Dublin, Ohio, as a minimal set of fifteen descriptive elements. By 2000, the growing needs of the metadata community demanded additional refinements -- sub-properties, range constraints, and supporting classes. The /elements/1.1/ namespace was created in 2000 to give the original fifteen elements stable RDF URIs, while the /terms/ namespace followed in 2001 for new terms coined outside that original set.
In 2008, the original fifteen elements were mirrored into the /terms/ namespace with formal semantic constraints, creating parallel pairs such as dc:date (untyped) and dcterms:date (with a literal range). While both remain valid, DCMI encourages adoption of the /terms/ namespace for new work. The most useful properties and classes from this expanded vocabulary were published as ISO 15836-2:2019, complementing the original element set standardized as ISO 15836-1:2017.
Purpose & Scope
DCMI Metadata Terms provides a general-purpose vocabulary for describing resources across domains. It is designed for use in Linked Data contexts through its RDF expression, but its natural-language definitions are intentionally useful outside RDF -- in XML, JSON, relational databases, and other environments.
The vocabulary spans four namespaces:
- http://purl.org/dc/terms/ -- the recommended namespace containing approximately 55 properties and 22 classes
- http://purl.org/dc/elements/1.1/ -- the legacy namespace for the original fifteen elements
- http://purl.org/dc/dcmitype/ -- the DCMI Type Vocabulary (12 resource type classes)
- http://purl.org/dc/dcam/ -- terms used in describing DCMI vocabularies themselves
Key Elements / Properties
The /terms/ namespace defines 55 properties. Among the most widely used:
| Property | Definition | Notes |
|---|---|---|
| title | A name given to the resource | |
| creator | An entity primarily responsible for making the resource | Range: Agent |
| subject | The topic of the resource | |
| description | An account of the resource | |
| publisher | An entity responsible for making the resource available | Range: Agent |
| date | A point or period of time associated with an event in the lifecycle of the resource | Range: Literal |
| type | The nature or genre of the resource | |
| format | The file format, physical medium, or dimensions of the resource | |
| identifier | An unambiguous reference to the resource within a given context | |
| language | A language of the resource | Range: LinguisticSystem |
| rights | Information about rights held in and over the resource | |
| license | A legal document giving official permission to do something with the resource | Range: LicenseDocument |
| spatial | Spatial characteristics of the resource | |
| temporal | Temporal characteristics of the resource | |
| conformsTo | An established standard to which the described resource conforms | Range: Standard |
Additional properties cover bibliographic relationships (isPartOf, hasPart, isVersionOf, replaces, requires), collection management (accrualMethod, accrualPeriodicity, accrualPolicy), and provenance.
The vocabulary also defines 22 classes (Agent, AgentClass, BibliographicResource, FileFormat, Frequency, Jurisdiction, LicenseDocument, LinguisticSystem, Location, and others), 9 vocabulary encoding schemes (DDC, LCC, LCSH, MESH, TGN, UDC, among others), and 12 syntax encoding schemes (ISO3166, ISO639-2, W3CDTF, and others).
Serializations & Technical Formats
DCMI Metadata Terms is expressed as four RDF schemas corresponding to the four namespaces. Term URIs resolve to the human-readable specification document in a browser and to the appropriate RDF schema when accessed programmatically. Official serializations are available in RDF/XML and Turtle, with JSON-LD contexts also in common use.
The common namespace prefixes are:
dcterms:for http://purl.org/dc/terms/dc:for http://purl.org/dc/elements/1.1/dcmitype:for http://purl.org/dc/dcmitype/dcam:for http://purl.org/dc/dcam/
Governance & Maintenance
DCMI Metadata Terms is maintained by the DCMI Usage Board under the organizational umbrella of the Dublin Core Metadata Initiative, which operates as a project of ASIS&T. The current version was issued on 2020-01-20, carrying the status of "DCMI Recommendation." Changes follow a community review process, and a complete version history is published on the DCMI website.
Notable Implementations
DCMI Metadata Terms is one of the most widely adopted metadata vocabularies in existence. It is used across library systems, digital repositories (DSpace, Fedora, EPrints), government open data portals, cultural heritage platforms, and scientific data infrastructure. The vocabulary serves as a foundational building block in numerous application profiles, including the DCAT vocabulary for data catalogs and the Europeana Data Model for cultural heritage aggregation.
Related Standards
- Dublin Core Metadata Element Set (DCES) -- the original fifteen-element subset, now a subset of DCMI Metadata Terms
- DCMI Type Vocabulary -- the twelve resource type classes, published as Section 7 of this specification
- DCMI Abstract Model -- the conceptual framework underpinning Dublin Core vocabularies