Note: you are viewing the development version of See How we work for more details.

Organization of Schemas

The schemas are a set of 'types', each associated with a set of properties. The types are arranged in a hierarchy.
The vocabulary currently consists of 806 Types, 1476 Properties 14 Datatypes, 90 Enumerations and 480 Enumeration members.

Browse the full hierarchy in HTML:
Look up a term using the TermFinder:

Or you can jump directly to a commonly used type:
See also the releases page for recent updates and project history.

We also have a small set of primitive data types for numbers, text, etc. More details about the data model, etc. are available here.

Developer information / Download Machine Readable files (RDF, JSON-LD, etc):


As has grown, we have explored various mechanisms for community extension as a way of adding more detailed descriptive vocabulary that builds on the core. Some areas of were developed as "named extensions", and have dedicated entry pages. We previously called these "hosted" extensions, but they are best considered simply as views into a single collection of schema definitions.

Hosted Sections

For example, via the auto section there is a property for emissionsCO2, and via the bib section we have a property publisherImprint. However, from the perspective of a publisher, these are simply properties.

We have a few of these sections:

Note: the 'pending' and 'meta' hosted sections are part of's schema development process.

We use the 'pending' section as a staging area for new terms that are under discussion and review. Implementors and publishers are cautioned that terms in the pending section may lack consensus and that terminology and definitions could still change significantly after community and steering group review. Consumers of data who encourage use of such terms are strongly encouraged to update implementations and documentation to track any evolving changes, and to share early implementation feedback with the wider community.

The 'meta' section is primarily for vocabulary used internally within to support technical definitions and site functionality. These terms are not intended for general usage in the public Web.

Attic is a special area where terms are archived when deprecated from the core and other sections, or removed from pending as not accepted into the full vocabulary. References to terms in the attic area are not normally displayed unless accessed via the term identifier or via the home page. Implementors and data publishers are cautioned not to use terms in the attic area.

Unlike other core and section terms, these areas may be updated at any time without the need for a full release.

External Extensions

The steering group does not officially approve external extensions - they are fully independent. We list here some notable extensions that extend in interesting and useful ways.