DCMIThe DCMI Type Vocabulary is a controlled list of twelve broad classes maintained by the Dublin Core Metadata Initiative for categorizing the nature or genre of a resource. Used in conjunction with the Dublin Core type property, it provides a simple, widely recognized set of terms that help users and systems distinguish between fundamentally different kinds of resources -- from textual documents and datasets to physical objects, software, and events.
Background
The need for a standardized set of resource type terms emerged alongside the original Dublin Core Metadata Element Set in the late 1990s. The Dublin Core type element invites metadata creators to classify the nature of a resource, but without a shared vocabulary the resulting values were inconsistent and difficult to process. The DCMI Type Vocabulary was established to address this gap, with its own namespace (http://purl.org/dc/dcmitype/) created in 2001.
Originally published as a standalone DCMI Recommendation, the type vocabulary is now documented as Section 7 of the consolidated DCMI Metadata Terms specification. Each type is defined as an RDF class within the /dcmitype/ namespace and is a member of the DCMIType vocabulary encoding scheme.
Purpose & Scope
The vocabulary provides twelve mutually understandable categories for the dc:type or dcterms:type property. It is intentionally broad -- a resource described as dcmitype:Image might be a photograph, a painting, a diagram, or a map. More granular type distinctions are left to domain-specific vocabularies, while the DCMI Type Vocabulary establishes a shared baseline.
The twelve classes are:
| Class | Definition |
|---|---|
| Collection | An aggregation of resources |
| Dataset | Data encoded in a defined structure |
| Event | A non-persistent, time-based occurrence |
| Image | A visual representation other than text |
| InteractiveResource | A resource requiring interaction from the user to be understood, executed, or experienced |
| MovingImage | A series of visual representations imparting an impression of motion when shown in succession |
| PhysicalObject | An inanimate, three-dimensional object or substance |
| Service | A system that provides one or more functions |
| Software | A computer program in source or compiled form |
| Sound | A resource primarily intended to be heard |
| StillImage | A static visual representation |
| Text | A resource consisting primarily of words for reading |
Two subclass relationships exist: MovingImage and StillImage are both subclasses of Image.
Serializations & Technical Formats
The vocabulary is expressed in RDF using the namespace http://purl.org/dc/dcmitype/. Each class URI follows the pattern http://purl.org/dc/dcmitype/{ClassName}, for example http://purl.org/dc/dcmitype/Text. The vocabulary is available as part of the DCMI RDF schemas in RDF/XML and Turtle serializations, with JSON-LD contexts also in widespread use. The common namespace prefix is dcmitype:.
Governance & Maintenance
The DCMI Type Vocabulary is maintained by the DCMI Usage Board as part of the broader DCMI Metadata Terms. The current version was issued on 2020-01-20. The vocabulary has been deliberately stable, with changes following the same community review process as other DCMI terms. The twelve types have remained consistent since the vocabulary's early development, with MovingImage and StillImage added as refinements of Image.
Notable Implementations
The DCMI Type Vocabulary is used wherever Dublin Core metadata is created, which includes thousands of digital repositories, library catalogs, open data portals, and cultural heritage platforms worldwide. Repository software such as DSpace, Fedora, and EPrints typically expose DCMI type values in their metadata. The vocabulary is also referenced by other standards -- for example, DCAT and the Europeana Data Model recognize DCMI Type values for resource classification.
Related Standards
- DCMI Metadata Terms -- the parent specification that contains this vocabulary as Section 7
- Dublin Core Metadata Element Set -- defines the
typeproperty for which this vocabulary provides values - DCAT (Data Catalog Vocabulary) -- references DCMI Type terms for dataset classification