World Wide Web Consortium (W3C)

Created on Aug 14th, 2020

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. Homepage:


This is a vocabulary collection utilized by XHTML Family modules and document types using XHTML Modularization, including XHTML Role and XHTML + RDFa as defined in rdfa-syntax.

Version: 1.0.0

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

A vocabulary for representing latitude, longitude and altitude information in the WGS84 geodetic reference datum. WGS stands for the World Geodetic Survey.

Version: 1.22.0

An RDF vocabulary for relating SW vocabulary terms to their status.

Version: 2.0.0

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 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: 2014-05-22

An ontology for units of measure.

Version: 1.2.0

The User Interface ontology allows the definition of forms for processing RDF model data, and include a bootstrap form for editing forms. It allows user interface hints such as background colors, can be associated with objects and classes.

Version: 2020-03-22

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

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

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

An RDF vocabulary for describing the basic structure and content of concept schemes such as thesauri, classification schemes, subject heading lists, taxonomies, 'folksonomies', other types of controlled vocabulary, and also concept schemes embedded in glossaries and terminologies.

Version: 2008-05

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

A SHACL shapes graph to validate SHACL shapes graphs.

Version: 2017-04-04

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

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

Version: 1.1.0

Named Graphs is the idea that having multiple RDF graphs in a single document/repository and naming them with URIs provides useful additional functionality built on top of the RDF Recommendations.

Named Graphs and corresponding technologies are currently developed by participants of the Semantic Web Interest Group. The intent is to introduce them into the W3C process in an appropriate way once initial versions are finished.

Version: 1.0.0

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

Version: 1.1.0

This Model Library for Quantities, Units, Dimensions and Values (QUDV).

This ontology is partially based on the SysML QUDV (Quantities, Units, Dimensions and Values) proposed by a working group of the SysML 1.2 Revision Task Force (RTF), working in close coordination with the OMG MARTE specification group. This model library is specified in a UML/SysML class/block diagram in the OMG SysML, Version 1.2 specification. This model is described in OMG SysML, Version 1.2 Appendix C.4 Model Library for Quantity Kinds and Units. The QUDV model has also been represented in the form of an ontology using a formal ontology definition language. The resulting OWL ontology, called the QUDV ontology has been published by members of the QUDV working group of the SysML 1.2 Revision Task Force (RTF). OMG SysML is a trademark of OMG (see for the conditions of use of the OMG SysML, Version 1.2 specification).

In order to generalize its potential usage and alignment with other standardization efforts concerning quantities and units, the QU ontology has been further developed as a complement to the Agriculture Meteorology example showcasing the ontology developed by the W3C Semantic Sensor Networks incubator group (SSN-XG).

Version: 1.2.0

Vocabulary for representing pointers ― entities that permit identifying a portion or segment of a piece of content ― making use of the Resource Description Framework (RDF). It also describes a number of specific types of pointers that permit portions of a document to be referred to in different ways. When referring to a specific part of, say, a piece of web content, it is useful to be able to have a consistent manner by which to refer to a particular segment of a web document, to have a variety of ways by which to refer to that same segment, and to make the reference robust in the face of changes to that document. This specification is part of the Evaluation And Report Language (EARL) but can be reused in other contexts too.

Version: 1.0.0

Unique identifiers for the OWL 2 Profiles:

Note that, strictly speaking, OWL DL and OWL Full are not referred to, formally, as “profiles” by the OWL 2 Profiles specification. However, “each profile is defined as a syntactic restriction of the OWL 2 Structural Specification, i.e., as a subset of the structural elements that can be used in a conforming ontology,…” (see the OWL 2 Document Overview). In this sense, and for practical purposes, including a URI for OWL DL and Full is correct. Indeed, OWL DL can be seen as a sytactic restriction of OWL that is particularly well suited for OWL 2 Direct Semantics, whereas OWL Full is a “profile” without any syntactic restriction, and is usually associated with the usage of the OWL 2 RDF-Based Semantics. Note also that there are no separate URIs for the 2004 version of OWL DL; OWL 2 DL, published in 2008 supersede that version. Nor is there a URI for OWL Lite.

Version: 2011-12-06

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 rdfs:isDefinedBy 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

This vocabulary was originally openly-editable at The editing interface has been retired and this data dump published in its place.

Version: 1.0.0

Vocabulary for describing organizational structures, specializable to a broad variety of types of organization.

Version: 0.8.0

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

An extension vocabulary for chain relations in ontologies.

Version: 1.0.0

This is a vocabulary for describing relationships between linked data objects and things fetched from the web.

Version: 1.15.0

Representation of quality categories and dimensions from Amrapali Zaveri, Anisa Rula, Andrea Maurino, Ricardo Pietrobon, Jens Lehmann, Sören Auer. 2016. “Quality Assessment for Linked Data: A Survey” in Semantic Web, Vol. 7, No. 1, pp. 63-93 (

Version: 1.0.0

The i18n namespace is used for describing combinations of language tag and base direction in RDF literals.

It is used as an alternative mechanism for describing the BCP47 language tag and base direction of RDF literals that would otherwise use the xsd:string or rdf:langString datatypes.

Version: 1.0.0

A vocabulary that defines a collection of RDF classes and properties that represent the HTTP vocabulary as defined by the HTTP specification RFC2616. These RDF terms can be used to record HTTP or secure HTTP request and response messages in RDF format, such as by automated Web accessibility evaluation tools that want to describe Web resources, including the various headers exchanged between the client and server during content negotiation.

Version: 2011-04-29