World Wide Web Consortium (W3C)

w3cCreated on Apr 30th, 2018

The World Wide Web Consortium (W3C) is an international community where Member organizations, a full-time staff, and the public work together to develop Web standards. Led by Web inventor and Director Tim Berners-Lee and CEO Jeffrey Jaffe, W3C's mission is to lead the Web to its full potential. Contact W3C for more information.



This ontology partially describes the built-in classes and properties that together form the basis of the RDF/XML syntax of OWL 2. The content of this ontology is based on Tables 6.1 and 6.2 in Section 6.4 of the OWL 2 RDF-Based Semantics specification, available at

Please note that those tables do not include the different annotations (labels, comments and links) used in this file. Also note that the descriptions provided in this ontology do not provide a complete and correct formal description of either the syntax or the semantics of the introduced terms (please see the OWL 2 recommendations for the complete and normative specifications).

Furthermore, the information provided by this ontology may be misleading if not used with care. This ontology SHOULD NOT be imported into OWL ontologies. Importing this file into an OWL 2 DL ontology will cause it to become an OWL 2 Full ontology and may have other, unexpected, consequences.

Version: 2.0.0

RDF Schema provides a data-modelling vocabulary for RDF data. RDF Schema is an extension of the basic RDF vocabulary.

Version: 1.1.0

SHACL Shapes Constraint Language is a language for validating RDF graphs against a set of conditions. These conditions are provided as shapes and other constructs expressed in the form of an RDF graph. RDF graphs that are used in this manner are called “shapes graphs” in SHACL and the RDF graphs that are validated against a shapes graph are called “data graphs”. As SHACL shape graphs are used to validate that data graphs satisfy a set of conditions they can also be viewed as a description of the data graphs that do satisfy these conditions. Such descriptions may be used for a variety of purposes beside validation, including user interface building, code generation and data integration.

Version: 1.0.0

The Web Annotation Vocabulary specifies the set of RDF classes, predicates and named entities that are used by the Web Annotation Data Model. It also lists recommended terms from other ontologies that are used in the model, and provides the JSON-LD Context and profile definitions needed to use the Web Annotation JSON serialization in a Linked Data context.

Version: 1.0.0

The Simple Knowledge Organization System (SKOS) is a common data model for sharing and linking knowledge organization systems via the Semantic Web.This document provides a brief description of the SKOS Vocabulary.

For detailed information about the SKOS Recommendation, please consult the SKOS Reference or the SKOS Primer.

Version: 1.2.0

This is the RDF Schema for the RDF vocabulary terms in the RDF Namespace, defined in RDF Concepts.

Version: 1.1.0

Semantic Web Application Platform (SWAP) or, if you like, Semantic Web Area for Play… visiting RDF and all points west. Working toward the SWELL langauge, MIT-LCS's advanced development prototyping of tools and langauges for the Semantic Web.

Version: 1.52.0

An RDF representation of XHTML 2.0's built-in link types. It is based on the Metainformation Attributes Module of XHTML2, and uses W3C's RDF Schema (RDFS) and Web Ontology (OWL) languages to describe several kinds of relationship that can hold between information resources.

Version: 1.53.0

OWL-Time is an OWL-2 DL ontology of temporal concepts, for describing the temporal properties of resources in the world or described in Web pages. The ontology provides a vocabulary for expressing facts about topological (ordering) relations among instants and intervals, together with information about durations, and about temporal position including date-time information. Time positions and durations may be expressed using either the conventional (Gregorian) calendar and clock, or using another temporal reference system such as Unix-time, geologic time, or different calendars.

Version: 1.0.0

A mapping of the vCard specification to RDF/OWL. The goal is to promote the use of vCard for the description of people and organizations utilizing semantic web techniques and allowing compatibility with traditional vCard implementations.

Version: 1.0.0

An ontology for units of measure.

Version: 1.2.0

VoID is an RDF Schema vocabulary for expressing metadata about RDF datasets. It is intended as a bridge between the publishers and users of RDF data, with applications ranging from data discovery to cataloging and archiving of datasets. This document is a detailed guide to the VoID vocabulary. It describes how VoID can be used to express general metadata based on Dublin Core, access metadata, structural metadata, and links between datasets. It also provides deployment advice and discusses the discovery of VoID descriptions.

Version: 1.0.0

A vocabulary for representing latitude, longitude and altitude information in the WGS84 geodetic reference datum.

Version: 1.22.0

The Simple Knowledge Organization System (SKOS) is a common data model for sharing and linking knowledge organization systems via the Semantic Web. SKOS-XL defines an extension for the Simple Knowledge Organization System, providing additional support for describing and linking lexical entities.This document provides a brief description of the SKOS-XL vocabulary.

Version: 1.4.0

The Data Quality Vocabulary (DQV) provides a framework in which the quality of a dataset can be described, whether by the dataset publisher or by a broader community of users. It does not provide a formal, complete definition of quality, rather, it sets out a consistent means by which information can be provided such that a potential user of a dataset can make his/her own judgment about its fitness for purpose.

Version: 1.0.0

DCAT is an RDF vocabulary designed to facilitate interoperability between data catalogs published on the Web. This document defines the schema and provides examples for its use.

DCAT enables a publisher to describe datasets and data services in a catalog using a standard model and vocabulary that facilitates the consumption and aggregation of metadata from multiple catalogs. This can increase the discoverability of datasets and data services. It also makes it possible to have a decentralized approach to publishing data catalogs and makes federated search for datasets across catalogs in multiple sites possible using the same query mechanism and structure. Aggregated DCAT metadata can serve as a manifest file as part of the digital preservation process.

Version: 2.0.0

An extension vocabulary for chain relations in ontologies.

  • Namespace: (alias o2) is a unique, top-level Class URI for specific file formats. Media types do not uniquely identify file formats (eg, serialization formats for various abstract concepts), because not all specific cases do have distinct media types, instances in this class can be used instead for proper identification.

Although the URI-s themselves refer to non-informational resources (ie, they are abstract identifiers), they can be dereferenced. Dereferencing leads to informational resources in XHTML, RDF/XML, or Turtle equivalents, depending on content negotiation.

The namespace name is intended for use with the PROV family of documents that support the interchange of provenance on the web. Please read the overview first. The terms within this namespace are defined in these specifications:

There are many situations where it would be useful to be able to publish multi-dimensional data, such as statistics, on the web in such a way that it can be linked to related data sets and concepts. The Data Cube vocabulary provides a means to do this using the W3C RDF (Resource Description Framework) standard. The model underpinning the Data Cube vocabulary is compatible with the cube model that underlies SDMX (Statistical Data and Metadata eXchange), an ISO standard for exchanging and sharing statistical data and metadata among organizations. The Data Cube vocabulary is a core foundation which supports extension vocabularies to enable publication of other aspects of statistical data flows or other multi-dimensional data sets.

This vocabulary describes SPARQL service description, a method for discovering, and vocabulary for describing SPARQL services made available via the SPARQL 1.1 Protocol for RDF. These descriptions provide a mechanism by which a client or end user can discover information about the SPARQL service such as supported extension functions and details about the available dataset.