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<!DOCTYPE html>
<html lang="en" dir="ltr">
<head>
<title>Data Catalog Vocabulary (DCAT) - Version 3</title>
<meta content="text/html; charset=utf-8" http-equiv="content-type" />
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<script class="remove" src="https://www.w3.org/Tools/respec/respec-w3c" defer></script>
<script class="remove" src="config.js"></script>
<!--
<link rel="stylesheet" type="text/css" href="style.css">
<link rel="stylesheet" type="text/css" href="small.css" media="only all and (max-width: 649px)">
-->
<style>
table.simple {width:100%;}
#table-sdo-mapping th:first-child ,
#table-sdo-mapping td:first-child {text-align:right;}
.prop-list {columns:4;}
</style>
</head>
<body>
<!-- Disclaimer -->
<aside class="ednote">
<p>This document presents advancements in the discussion made on DCAT 3 within DXWG group. It extends DCAT 2 [[?VOCAB-DCAT-2]] with terms and guidelines on inverse properties, versioning, and dataset series (see sections <a href="#inverse-properties"></a>, <a href="#dataset-versions"></a> and <a href="#dataset-series"></a>), and by including terms for specifying the checksum of a distribution (see <a href="#Property:distribution_checksum"></a> and <a href="#Class:Checksum"></a>).</p>
</aside>
<aside class="note">
<p>DCAT 3 supersedes DCAT 2 [[?VOCAB-DCAT-2]], but it does not make it obsolete. DCAT 3 maintains the DCAT namespace as its terms preserve backward compatibility with DCAT 2. DCAT 3 relaxes constraints and adds new classes and properties, but these changes do not break the definition of previous terms.</p>
<p>Any new implementation is expected to adopt DCAT 3, while the existing implementations do not need to upgrade to it, unless they want to use the new features. In particular, current DCAT 2 deployments that do not overlap with the DCAT 3 new features (e.g., versioning, dataset series and inverse properties) don't need to change anything to remain in conformance with DCAT 3.
</p>
</aside>
<section id="abstract">
<p>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.</p>
<p>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.</p>
<p style="text-indent: 100px;">The namespace for DCAT terms is <code>http://www.w3.org/ns/dcat#</code></p>
<p style="text-indent: 100px;">The suggested prefix for the DCAT namespace is <code>dcat</code></p>
<!--
<p style="text-indent: 100px;">The (revised) DCAT vocabulary is available <a href="https://w3c.github.io/dxwg/dcat/rdf/dcat.ttl">here</a>.</p>
-->
</section>
<section id="sotd">
<!--aside class="ednote">
<p>This section will be updated to cover DCAT3 work in a later draft</p>
</aside-->
<p>
This document defines a major revision of the DCAT 2 vocabulary ([[?VOCAB-DCAT-2]]) in response to use cases, requirements and community experience which could not be considered during the previous vocabulary development. This revision extends the original DCAT standard in line with community practice while supporting diverse approaches to data description and dataset exchange. The main changes to the DCAT vocabulary have been:
</p>
<ul>
<li>addition of <a href="#Property:distribution_checksum"><code>spdx:checksum</code></a> property and <a href="#Class:Checksum"><code>spdx:Checksum</code></a> class to provide digest for DCAT distributions</li>
<li>addition of properties for supporting versioning, e.g., <a href="#Property:resource_version"><code>dcat:version</code></a>, <a href="#Property:resource_previous_version"><code>dcat:previousVersion</code></a>, <a href="#Property:resource_has_current_version"><code>dcat:hasCurrentVersion</code></a>, see <a href="#dataset-versions"></a></li>
<li>addition of a <a href="#Class:Dataset_Series"><code>dcat:DatasetSeries</code></a> class and properties for representing Dataset Series, see <a href="#dataset-series"></a></li>
</ul>
<p>
This new version of the vocabulary updates and expands the original but preserves backward compatibility. A full list of the significant changes (with links to the relevant GitHub issues) is described in <a href="#changes"></a>.
</p>
<p>
The exit criteria for <abbr title="Candidate Recommendation">CR</abbr> focused on v3 new features that replicate features that were included in application profiles of v2 as a way of remedying missing and necessary elements. <!--The exit criteria also included recent commitments by organisations such as EC Joinup to <a href='https://joinup.ec.europa.eu/solution/abr-specification-registry-registries/document/specification-registry-registries-version-meeting-september'>adopt the DCAT v2 model</a> in their work.-->
Implementation will be evidenced by showing use of the new properties/classes (or terms with equivalent meaning) in implementations of catalogs.
</p>
<p>
<a href="https://github.com/w3c/dxwg/issues?utf8=%E2%9C%93&q=is%3Aissue+is%3Aopen+label%3Adcat+">Issues, requirements, and features</a> that have been considered and discussed by the Data eXchange Working Group but have not been addressed due to lack of maturity or consensus are collected in GitHub. Those believed to be a priority for a future release are in the milestone <a href="https://github.com/w3c/dxwg/milestone/31">DCAT Future Priority Work</a>.
</p>
<h3 id="dcat_history">DCAT history</h3>
<p>The original DCAT vocabulary was developed and hosted at the <a href="http://www.deri.ie">Digital Enterprise Research Institute (DERI)</a>, then refined by the <a href="http://www.w3.org/egov/">eGov Interest Group</a>, and finally standardized in 2014 [[?VOCAB-DCAT-1]] by the <a href="http://www.w3.org/2011/gld/">Government Linked Data (GLD)</a> Working Group.</p>
<p>A second recommended revision of DCAT, DCAT 2 [[?VOCAB-DCAT-2]], was developed by the <a href="https://www.w3.org/2017/dxwg/">Dataset Exchange Working Group</a> in response to a new set of Use Cases and Requirements [[?DCAT-UCR]] gathered from peoples' experience with the DCAT vocabulary from the time of the original version, and new applications that were not considered in the first version. </p>
<p>This version of DCAT, DCAT 3, was developed by the <a href="https://www.w3.org/2017/dxwg/">Dataset Exchange Working Group</a>, considering some of the more pressing use cases and requests among those left unaddressed in the previous standardization round. A summary of the changes from [[?VOCAB-DCAT-2]] is provided in <a href="#changes"></a>. </p>
<h3 id="external_terms">External terms</h3>
<p>DCAT incorporates terms from pre-existing vocabularies where stable terms with appropriate meanings could be found, such as <a href="http://xmlns.com/foaf/0.1/homepage"><code>foaf:homepage</code></a> and <a href="http://purl.org/dc/terms/title"><code>dcterms:title</code></a>.
Informal summary definitions of the externally-defined terms are included in the DCAT vocabulary for convenience, while authoritative definitions are available in the normative references.
Changes to definitions in the references, if any, supersede the summaries given in this specification.
Note that conformance to DCAT (<a href="#conformance"></a>) concerns usage of only the terms in the DCAT vocabulary specification, so possible changes to other external definitions will not affect the conformance of DCAT implementations.</p>
<h3 id="please_send_comments">Please send comments</h3>
The Working Group invited publishers to describe their catalogs and datasets with the revised version of DCAT described in this document and to report their implementations following <a href="https://github.com/w3c/dxwg/wiki/DCAT-implementation-evidence">the instruction to reporting DCAT revised implementations</a>. This information and subsequent analysis is published in the <a href="https://w3c.github.io/dxwg/dcat-implementation-report/">implementation report.</a>
</section>
<section class="introductory" id="issue-summary">
</section>
<section id="introduction" class="informative">
<h2>Introduction</h2>
<p>Sharing data resources among different organizations, researchers, governments and citizens requires the provision of metadata.
This is irrespective of the data being open or not.
DCAT is a vocabulary for publishing data catalogs on the Web, which was originally developed in the context of government data catalogs
such as <a href="https://www.data.gov/">data.gov</a> and <a href="https://data.gov.uk">data.gov.uk</a>, but it is also applicable and has been used in other contexts.
<p>
<p>
DCAT 3 has extended the previous version to support further use cases and requirements [[?DCAT-UCR]].
These include the possibility of cataloging other resources in addition to
datasets, such as dataset series. The revision also supports describing versioning of resources. Guidance on how to use inverse properties is provided.
</p>
<p>
DCAT provides RDF classes and properties to allow datasets and data services to be described and included in a catalog.
The use of a standard model and vocabulary facilitates the consumption and aggregation of metadata from multiple catalogs, which can:</p>
<ol>
<li>
increase the discoverability of datasets and data services
</li>
<li>
allow federated search for datasets across catalogs in multiple sites
</li>
</ol>
<p>
Data described in a catalog can come in many formats, ranging from spreadsheets, through XML and RDF to various specialized formats.
DCAT does not make any assumptions about these serialization formats of the datasets but it does
distinguish between the abstract dataset and its different manifestations or distributions.
</p>
<p>
Data is often provided through a service which supports selection of an extract, sub-set, or combination of existing data, or of new data generated by some data processing function.
DCAT allows the description of a data access service to be included in a catalog.
</p>
<p>
Complementary vocabularies can be used together with DCAT to provide more detailed format-specific information.
For example, properties from the VoID vocabulary [[?VOID]] can be used within DCAT to express various statistics about a dataset if that dataset is in RDF format.
</p>
<p>
This document does not prescribe any particular method of deploying data catalogs expressed in DCAT.
DCAT information can be presented in many forms including RDF accessible via SPARQL endpoints, embedded in HTML pages as [[?HTML-RDFa]], or serialized as RDF/XML [[?RDF-SYNTAX-GRAMMAR]], [[?N3]], [[?Turtle]], [[?JSON-LD]] or other formats.
Within this document the examples use [[?Turtle]] because of its readability.
</p>
</section>
<section id="motivation" class="informative">
<h2>Motivation for change</h2>
<!--aside class="ednote">
<p>This section will be updated to cover DCAT3 work in a later draft</p>
</aside-->
<p>The original Recommendation [[?VOCAB-DCAT-20140116]] published in January 2014 provided the basic framework for describing datasets. It made an important distinction between a <i>dataset</i> as an abstract idea and a <i>distribution</i> as a manifestation of the dataset. Although DCAT has been widely adopted, it has become clear that the original specification lacked a number of essential features that were added either through the mechanism of a profile, such as the European Commission's DCAT-AP [[?DCAT-AP]], or the development of larger vocabularies that to a greater or lesser extent built upon the base standard, such as the Healthcare and Life Sciences Community Profile [[?HCLS-Dataset]], the Data Tag Suite [[?DATS]] and more. DCAT 2 [[?VOCAB-DCAT-2]] was developed to address the specific shortcomings that have come to light through the experiences of different communities, the aim being to improve interoperability between the outputs of these larger vocabularies.
For example, DCAT 2 provided classes, properties and guidance to address <a href="#dereferenceable-identifiers">identifiers</a>, <a href="#quality-information">dataset quality information</a>, and <a href="#data-citation">data citation</a> issues.</p>
<p>This revision, DCAT 3, updates the specification throughout. Significant changes from the 2014 Recommendation and DCAT 2 are marked within the text using "Note" sections, as well as being described in <a href="#changes"></a>.</p>
</section>
<section id="namespaces">
<h2 >Namespaces</h2>
<p>The namespace for DCAT is <code>http://www.w3.org/ns/dcat#</code>.
DCAT also makes extensive use of terms from other vocabularies, in particular Dublin Core [[?DCTERMS]].
DCAT defines a minimal set of classes and properties of its own.</p>
<section>
<h3>Normative namespaces</h3>
<p>Namespaces and prefixes used in normative parts of this recommendation are shown in the following table.</p>
<table id="table-namespaces" class="simple">
<thead><tr><th>Prefix</th><th>Namespace IRI</th><th>Source</th></tr></thead>
<tbody>
<tr><td><code>dc</code></td><td><code>http://purl.org/dc/elements/1.1/</code></td><td>[[DCTERMS]]</td></tr>
<tr><td><code>dcat</code></td><td><code>http://www.w3.org/ns/dcat#</code></td><td>[[VOCAB-DCAT]]</td></tr>
<tr><td><code>dcterms</code></td><td><code>http://purl.org/dc/terms/</code></td><td>[[DCTERMS]]</td></tr>
<tr><td><code>dctype</code></td><td><code>http://purl.org/dc/dcmitype/</code></td><td>[[DCTERMS]]</td></tr>
<tr><td><code>foaf</code></td><td><code>http://xmlns.com/foaf/0.1/</code></td><td>[[FOAF]]</td></tr>
<tr><td><code>locn</code></td><td><code>http://www.w3.org/ns/locn#</code></td><td>[[LOCN]]</td></tr>
<tr><td><code>odrl</code></td><td><code>http://www.w3.org/ns/odrl/2/</code></td><td>[[ODRL-VOCAB]]</td></tr>
<tr><td><code>owl</code></td><td><code>http://www.w3.org/2002/07/owl#</code></td><td>[[OWL2-SYNTAX]]</td></tr>
<tr><td><code>prov</code></td><td><code>http://www.w3.org/ns/prov#</code></td><td>[[PROV-O]]</td></tr>
<tr><td><code>rdf</code></td><td><code>http://www.w3.org/1999/02/22-rdf-syntax-ns#</code></td><td>[[RDF-SYNTAX-GRAMMAR]]</td></tr>
<tr><td><code>rdfs</code></td><td><code>http://www.w3.org/2000/01/rdf-schema#</code></td><td>[[RDF-SCHEMA]]</td></tr>
<tr><td><code>skos</code></td><td><code>http://www.w3.org/2004/02/skos/core#</code></td><td>[[SKOS-REFERENCE]]</td></tr>
<tr><td><code>spdx</code></td><td><code>http://spdx.org/rdf/terms#</code></td><td>[[SPDX]]</td></tr>
<tr><td><code>time</code></td><td><code>http://www.w3.org/2006/time#</code></td><td>[[OWL-TIME]]</td></tr>
<tr><td><code>vcard</code></td><td><code>http://www.w3.org/2006/vcard/ns#</code></td><td>[[VCARD-RDF]]</td></tr>
<tr><td><code>xsd</code></td><td><code>http://www.w3.org/2001/XMLSchema#</code></td><td>[[XMLSCHEMA11-2]]</td></tr>
</tbody>
</table>
</section>
<section class="informative">
<h3>Non-normative namespaces</h3>
<p>Namespaces and prefixes used in examples and guidelines in the document and not from normative parts of the recommendation are shown in the following table.</p>
<table id="table-namespaces-examples" class="simple">
<thead><tr><th>Prefix</th><th>Namespace IRI</th><th>Source</th></tr></thead>
<tbody>
<tr><td><code>adms</code></td><td><code>https://www.w3.org/ns/adms#</code></td><td>[[?VOCAB-ADMS]]</td></tr>
<tr><td><code>dqv</code></td><td><code>http://www.w3.org/ns/dqv#</code></td><td>[[?VOCAB-DQV]]</td></tr>
<tr><td><code>earl</code></td><td><code>http://www.w3.org/ns/earl#</code></td><td>[[?EARL10-Schema]]</td></tr>
<tr><td><code>geosparql</code></td><td><code>http://www.opengis.net/ont/geosparql#</code></td><td>[[?GeoSPARQL]]</td></tr>
<tr><td><code>oa</code></td><td><code>http://www.w3.org/ns/oa#</code></td><td>[[?ANNOTATION-VOCAB]]</td></tr>
<tr><td><code>pav</code></td><td><code>http://purl.org/pav/</code></td><td>[[?PAV]]</td></tr>
<tr><td><code>sdmx-attribute</code></td><td><code>http://purl.org/linked-data/sdmx/2009/attribute#</code></td><td>[[?VOCAB-DATA-CUBE]]</td></tr>
<tr><td><code>sdo</code></td><td><code>https://schema.org/</code></td><td>[[?SCHEMA-ORG]]</td></tr>
<tr><td><code>xhv</code></td><td><code>http://www.w3.org/1999/xhtml/vocab#</code></td><td>[[XHTML-VOCAB]]</td></tr>
<!--
<tr><td><code>w3cgeo</code></td><td><code>http://www.w3.org/2003/01/geo/wgs84_pos#</code></td><td>[[?W3C-BASIC-GEO]]</td></tr>
-->
</tbody>
</table>
</section>
</section>
<section id="conformance">
<p>A data catalog conforms to DCAT if:</p>
<ul>
<li> Access to data is organized into datasets, distributions, and data-services. </li>
<li> An RDF description of the catalog itself, the corresponding cataloged resources, and distributions is available (but the choice of
RDF syntax, access protocol, and access policy are not mandated by this specification).</li>
<li> The contents of all metadata fields that are held in the catalog and that contain data about the catalog itself, the corresponding cataloged resources, and distributions are included in this RDF description and are expressed using the appropriate classes and properties from DCAT, except where no such class or property exists.</li>
<li> All classes and properties defined in DCAT are used in a way consistent with the semantics declared in this specification.</li>
</ul>
DCAT-compliant catalogs MAY include additional non-DCAT metadata fields and additional RDF data in the catalog's RDF description.
<p>
A <strong>DCAT profile</strong> is a specification for a data catalog that adds additional constraints to DCAT. A data catalog that conforms to the profile also conforms to DCAT. Additional constraints in a profile MAY include:
</p>
<ul>
<li> Cardinality constraints, including a minimum set of required metadata fields </li>
<li> Sub-classes and sub-properties of the standard DCAT classes and properties</li>
<li> Classes and properties for additional metadata fields not covered in DCAT vocabulary specification</li>
<li> Controlled vocabularies or IRI sets as acceptable values for properties</li>
<li> Requirements for specific access mechanisms (RDF syntaxes, protocols) to the catalog's RDF description</li>
</ul>
<!--NoBacklogNorCR p class="issue" data-number="430">
The requirement for a DCAT profile to conform to all of DCAT is under discussion.
</p-->
<aside class="note">
<p>The notion of <em>profile</em> used in this document denotes metadata specifications that the Dublin Core community would call <em>application profiles</em> [[?DCAP]].</p>
</aside>
</section>
<section id="vocabulary-overview" class="informative">
<h2>Vocabulary overview</h2>
<section id="dcat-scope">
<h3>DCAT scope</h3>
<p>DCAT is an RDF vocabulary for representing data catalogs.
DCAT is based around seven main classes (<a href="#fig-dcat-all-attributes"></a>):</p>
<ul>
<li>
<a href="#Class:Catalog"><code>dcat:Catalog</code></a> represents a catalog, which is a dataset in which each individual item is a metadata record describing some resource; the scope of <code>dcat:Catalog</code> is collections of metadata about <b>datasets</b> or <b>data services</b>.
</li>
<li>
<a href="#Class:Resource"><code>dcat:Resource</code></a> represents a dataset, a data service or any other resource that may be described by a metadata record in a catalog.
This class is not intended to be used directly, but is the parent class of <a href="#Class:Dataset"><code>dcat:Dataset</code></a>, <a href="#Class:Data_Service"><code>dcat:DataService</code></a> and <a href="#Class:Catalog"><code>dcat:Catalog</code></a>.
Member items in a catalog should be members of one of the sub-classes, or of a sub-class of these, or of a sub-class of <a href="#Class:Resource"><code>dcat:Resource</code></a> defined in a DCAT profile or other DCAT application.
<a href="#Class:Resource"><code>dcat:Resource</code></a> is effectively an extension point for defining a catalog of any kind of resource. <a href="#Class:Dataset"><code>dcat:Dataset</code></a> and <a href="#Class:Data_Service"><code>dcat:DataService</code></a> can be used for datasets and services which are not documented in any catalog.
</li>
<li>
<a href="#Class:Dataset"><code>dcat:Dataset</code></a> represents a collection of data, published or curated by a single agent or identifiable community. The notion of dataset in DCAT is broad and inclusive, with the intention of accommodating resource types arising from all communities. Data comes in many forms including numbers, text, pixels, imagery, sound and other multi-media, and potentially other types, any of which might be collected into a dataset.
</li>
<li>
<a href="#Class:Distribution"><code>dcat:Distribution</code></a> represents an accessible form of a dataset such as a downloadable file.
</li>
<li>
<a href="#Class:Data_Service"><code>dcat:DataService</code></a> represents a collection of operations accessible through an interface (<abbr title="Application Programming Interface">API</abbr>) that provide access to one or more datasets or data processing functions.
</li>
<li>
<a href="#Class:Dataset_Series"><code>dcat:DatasetSeries</code></a> is a dataset that represents a collection of datasets that are published separately, but share some common characteristics that group them.
</li>
<li>
<a href="#Class:Catalog_Record"><code>dcat:CatalogRecord</code></a> represents a metadata item in the catalog, primarily concerning the registration information, such as who added the item and when.
</li>
</ul>
<aside class="ednote" title="Class Diagram need to be updated">
<p>
Changes required for the class diagram are tracked in issue <a href="https://github.com/w3c/dxwg/issues/1320">#1320</a>.
</p>
</aside>
<figure id="fig-dcat-all-attributes">
<img alt="UML model of DCAT classes and properties" src="./images/dcat-all-attributes.svg">
<figcaption>
Overview of DCAT model, showing the classes of resources that can be members of a Catalog, and the relationships between them. Except where specifically indicated, DCAT does not provide cardinality constraints.
</figcaption>
</figure>
<aside class="note">
<p>
Along with the rest of <a href="#vocabulary-overview"></a>, this diagram is <b>non-normative</b>.
Furthermore, while the diagram uses UML-style class notation it should be interpreted following the usual RDF open-world assumptions around the presence/absence of properties, relationships, and their cardinality.
The properties shown in each class reflect those specified in the descriptions of classes in <a href="#vocabulary-specification"></a>.
Open arrow-heads indicate RDFS <i>sub-class-of</i> relationships (not object-oriented generalization).
To assist in understanding the full scope of each class, available properties are copied down from each '::super-class'.
<!--Cardinalities are shown in a few places to reinforce expectations, but these are not axiomatized or enforced in any way by this (normative) recommendation.-->
</p>
</aside>
<p>
A <b>dataset</b> in DCAT is defined as a "collection of data, published or curated by a single agent, and available for access or download in one or more serializations or formats".
A dataset is a conceptual entity, and can be represented by one or more <b>distributions</b> that serialize the dataset for transfer.
Distributions of a dataset can be provided via <b>data services</b>.
</p>
<p>
A data service typically provides selection, extraction, combination, processing or transformation operations over datasets that might be hosted locally or remote to the service.
The result of any request to a data service is a representation of a part or all of a dataset or catalog.
A data service might be tied to specific datasets, or its source data might be configured at request- or run-time.
A data distribution service allows selection and download of a distribution of a dataset or subset.
A data discovery service allows a client to find a suitable dataset.
Other kinds of data service include data transformation services, such as coordinate transformation services, re-sampling and interpolation services, and various data processing services, including simulation and modelling services.
Note that a data service in DCAT is a collection of operations or <b>API</b> which provides access to data.
An interactive user-interface is often available to provide convenient access to API operations, but its description is outside the scope of DCAT.
The details of a particular data service endpoint will often be specified through a description conforming to a standard service type, which complement the scope of the DCAT vocabulary itself.
</p>
<p>
Descriptions of datasets and data services can be included in a <b>catalog</b>.
A catalog is a kind of dataset whose member items are descriptions of datasets and data services.
Other types of things might also be cataloged, but the scope of DCAT is currently limited to datasets and data services.
To extend the scope of a catalog beyond datasets and data services it is recommended to define additional sub-classes of <a href="#Class:Resource"><code>dcat:Resource</code></a> in a DCAT profile or other DCAT application.
To extend the scope of service descriptions beyond data distribution services it is recommended to define additional sub-classes of <a href="#Class:Data_Service"><code>dcat:DataService</code></a> in a DCAT profile or other DCAT application.
</p>
<aside class="note">
<p>
The scope of DCAT 1 [[?VOCAB-DCAT-20140116]] was limited to catalogs of datasets.
A number of use cases for the revision [[?DCAT-UCR]] involve <b>data services</b> as members of a catalog - see <a data-cite="DCAT-UCR#ID6">§ <span class="secno">5.16 </span>DCAT Distribution to describe Web services</a> and
<a data-cite="DCAT-UCR#ID18">§ <span class="secno">5.18 </span>Modeling service-based data access</a>.
Hence, the scope of DCAT 2 includes both datasets and data services to enable these to be part of a DCAT conformant catalog.
Provision for catalogs to be composed of other catalogs is also made.
See Issue <a href="https://github.com/w3c/dxwg/issues/172">#172</a>.
</p>
<p>
Catalogs of other kinds of things might be designed following the DCAT pattern, e.g. dealing with facilities, instruments, samples and specimens, other physical artefacts, events or activities.
These are currently out of scope for DCAT, but might be defined through further sub-classes of <a href="#Class:Resource"><code>dcat:Resource</code></a>, which could be specified in a DCAT profile or other DCAT application.
</p>
</aside>
<p>A <b>catalog record</b> describes an entry in the catalog. Notice that while <a href="#Class:Resource"><code>dcat:Resource</code></a> represents the dataset or service itself, <a href="#Class:Catalog_Record"><code>dcat:CatalogRecord</code></a> is the record that describes the registration of an item in the catalog. The use of <a href="#Class:Catalog_Record"><code>dcat:CatalogRecord</code></a> is considered optional. It is used to capture provenance information about entries in a catalog explicitly. If this is not necessary then <a href="#Class:Catalog_Record"><code>dcat:CatalogRecord</code></a> can be safely ignored.</p>
</section>
<section id="dcat-rdf">
<h3>RDF considerations</h3>
<p id="owl2">
The DCAT vocabulary is an OWL2 ontology [[?OWL2-OVERVIEW]] formalized using [[?RDF-SCHEMA]].
Each class and property in DCAT is denoted by an <abbr title="Internationalized Resource Identifier">IRI</abbr> [[?RFC3987]].
Locally defined elements are in the namespace <a href="http://www.w3.org/ns/dcat#"><code>http://www.w3.org/ns/dcat#</code></a>.
Elements are also adopted from several external vocabularies, in particular [[?FOAF]], [[?DCTERMS]] and [[?PROV-O]]
</p>
<p id="blankNodes">
RDF allows resources to have global identifiers (<abbr title="Internationalized Resource Identifiers">IRIs</abbr>) or to be blank nodes.
Blank nodes can be used to denote resources without explicitly naming them with an IRI.
They can appear in the subject and object position of a triple [[?RDF11-PRIMER]].
For example, in many actual DCAT catalogs, distributions are represented as blank nodes nested inside the related dataset description.
While blank nodes can offer flexibility for some use cases, in a Linked Data context, blank nodes limit our ability to collaboratively annotate data.
A blank node resource cannot be the target of a link and it can't be annotated with new information from new sources.
As one of the biggest benefits of the Linked Data approach is that "anyone can say anything anywhere", use of blank nodes undermines some of the advantages we can gain from wide adoption of the RDF model.
Even within the closed world of a single application dataset, use of blank nodes can quickly become limiting when integrating new data [[?LinkedDataPatterns]].
For these reasons, it is recommended that instances of the DCAT main classes have a global identifier, and use of blank nodes is generally discouraged when encoding DCAT in RDF.
</p>
<p id="rdf-syntax">
All RDF examples in this document are written in Turtle syntax [[?Turtle]] and many are available from the <a href="https://github.com/w3c/dxwg/tree/gh-pages/dcat/examples">DXWG code repository</a>.
</p>
<aside class="note">
<p>
Each RDF example in this document is intended to demonstrate specific capabilities of DCAT, and therefore only shows a subset of all the potential properties and links which might appear in a complete DCAT resource.
</p>
</aside>
</section>
<section id="basic-example">
<h3>Basic example</h3>
<p>This example provides a quick overview of how DCAT might be used to represent a government catalog and its datasets. Titles, labels and keywords are provided both in English and Spanish to demonstrate the use of language tags.</p>
<p>First, the catalog description:
</p>
<aside id="ex-catalog" class="example">
<pre class="nohighlight turtle">
ex:catalog
a dcat:Catalog ;
dcterms:title "Imaginary Catalog"@en ;
dcterms:title "Catálogo imaginario"@es ;
rdfs:label "Imaginary Catalog"@en ;
rdfs:label "Catálogo imaginario"@es ;
foaf:homepage <http://dcat.example.org/catalog> ;
dcterms:publisher ex:transparency-office ;
dcterms:language <http://id.loc.gov/vocabulary/iso639-1/en> ;
dcat:dataset ex:dataset-001 , ex:dataset-002 , ex:dataset-003 ;
.
</pre>
</aside>
<p>The publisher of the catalog has the relative IRI <code>ex:transparency-office</code>. Further description of the publisher can be provided as in <a href="#ex-publisher"></a>:
</p>
<aside id="ex-publisher" class="example">
<pre class="nohighlight turtle">
ex:transparency-office
a foaf:Organization ;
rdfs:label "Transparency Office"@en ;
rdfs:label "Oficina de Transparencia"@es ;
.
</pre>
</aside>
<p>The catalog lists each of its datasets via the <code>dcat:dataset</code> property. In <a href="#ex-catalog"></a>, an example dataset was mentioned with the relative IRI <code>ex:dataset-001</code>. A possible description of it using DCAT is shown below:
</p>
<aside id="ex-dataset" class="example">
<pre class="nohighlight turtle">
ex:dataset-001
a dcat:Dataset ;
dcterms:title "Imaginary dataset"@en ;
dcterms:title "Conjunto de datos imaginario"@es ;
dcat:keyword "accountability"@en, "transparency"@en, "payments"@en ;
dcat:keyword "responsabilidad"@es, "transparencia"@es, "pagos"@es ;
dcterms:creator ex:finance-employee-001 ;
dcterms:issued "2011-12-05"^^xsd:date ;
dcterms:modified "2011-12-15"^^xsd:date ;
dcat:contactPoint <http://dcat.example.org/transparency-office/contact> ;
dcterms:temporal [ a dcterms:PeriodOfTime ;
dcat:startDate "2011-07-01"^^xsd:date ;
dcat:endDate "2011-09-30"^^xsd:date ;
];
dcat:temporalResolution "P1D"^^xsd:duration ;
dcterms:spatial <http://sws.geonames.org/6695072/> ;
dcat:spatialResolutionInMeters "30.0"^^xsd:decimal ;
dcterms:publisher ex:finance-ministry ;
dcterms:language <http://id.loc.gov/vocabulary/iso639-1/en> ;
dcterms:accrualPeriodicity <http://purl.org/linked-data/sdmx/2009/code#freq-W> ;
dcat:distribution ex:dataset-001-csv ;
.
</pre>
</aside>
<p>
Five distinct temporal descriptors are shown for this dataset.
The dataset publication and revision dates are shown in <a href="#Property:resource_release_date"><code>dcterms:issued</code></a> and <a href="#Property:resource_update_date"><code>dcterms:modified</code></a>.
For the frequency of update of the dataset in <a href="#Property:dataset_frequency"><code>dcterms:accrualPeriodicity</code></a>, we use an instance from the <a data-cite="VOCAB-DATA-CUBE#dsd-cog">content-oriented guidelines</a> developed as part of the W3C Data Cube Vocabulary [[?VOCAB-DATA-CUBE]] efforts.
The temporal coverage or extent is given in <a href="#Property:dataset_temporal"><code>dcterms:temporal</code></a> defining a <a href="#Class:Period_of_Time"><code>dcterms:PeriodOfTime</code></a> as a closed interval indicated by <a href="#Property:period_start_date"><code>dcat:startDate</code></a> and <a href="#Property:period_end_date"><code>dcat:endDate</code></a>.
The temporal resolution, which describes the minimum spacing of items within the dataset, is given in <a href="#Property:dataset_temporal_resolution"><code>dcat:temporalResolution</code></a> using the standard datatype <code>xsd:duration</code>.
</p>
<p>
Additionally, the spatial coverage or extent is given <a href="#Property:dataset_spatial"><code>dcterms:spatial</code></a> using a IRI from <a href="http://www.geonames.org/">Geonames</a>.
The spatial resolution, which describes the minimum spatial separation of items within the dataset, is given in <a href="#Property:dataset_spatial_resolution"><code>dcat:spatialResolutionInMeters</code></a> using the standard datatype <code>xsd:decimal</code>.
</p>
<p>
A contact point is provided where comments and feedback about the dataset can be sent.
Further details about the contact point, such as email address or telephone number, can be provided using vCard [[?VCARD-RDF]].
</p>
<p>One representation of the dataset <code>:dataset-001-csv</code> can be downloaded as a 5kB CSV file. This is
represented as an RDF resource of type <code>dcat:Distribution</code>.
</p>
<aside id="ex-distribution" class="example">
<pre class="nohighlight turtle">
ex:dataset-001-csv
a dcat:Distribution ;
dcat:downloadURL <http://dcat.example.org/files/001.csv> ;
dcterms:title "CSV distribution of imaginary dataset 001"@en ;
dcterms:title "distribución en CSV del conjunto de datos imaginario 001"@es ;
dcat:mediaType <http://www.iana.org/assignments/media-types/text/csv> ;
dcat:byteSize "5120"^^xsd:nonNegativeInteger ;
.
</pre>
</aside>
</section>
<section id="classifying-datasets">
<h3>Classifying datasets thematically</h3>
<p>The catalog classifies its datasets according to a set of domains represented by the relative IRI <code>:themes</code>. SKOS [[?SKOS-REFERENCE]] can be used to describe the domains used:
</p>
<aside id="ex-thematic-classification" class="example">
<pre class="nohighlight turtle">
:catalog dcat:themeTaxonomy :themes .
:themes
a skos:ConceptScheme ;
skos:prefLabel "A set of domains to classify documents"@en ;
.
:dataset-001 dcat:theme ex:accountability .</pre>
</aside>
<p>Notice that this dataset is classified under the domain represented by the relative IRI <code>:accountability</code>.
It is recommended to define the concept as part of the concepts scheme identified by the IRI <code>:themes</code> that was used to describe the catalog domains. An example SKOS description:
</p>
<aside id="ex-theme-accountability" class="example">
<pre class="nohighlight turtle">
ex:accountability
a skos:Concept ;
skos:inScheme ex:themes ;
skos:prefLabel "Accountability"@en ;
.</pre>
</aside>
</section>
<section id="classifying-dataset-types">
<h3>Classifying dataset types</h3>
<p>
The type or genre of a dataset can be indicated using the <a href="http://purl.org/dc/terms/type"><code>dcterms:type</code></a> property.
It is recommended that the value of the property is taken from a well governed and broadly recognised set of resource types,
such as the <a data-cite="?DCTERMS#section-7">DCMI Type Vocabulary</a> [[?DCTERMS]],
the <a href="https://id.loc.gov/vocabulary/marcgt.html">MARC Genre/Terms Scheme</a>,
the [[?ISO-19115-1]] <a href="https://standards.iso.org/iso/19115/resources/Codelists/gml/MD_ScopeCode.xml"><code>MD_Scope codes</code></a>,
the <a href="https://schema.datacite.org/meta/kernel-4.1/include/datacite-resourceType-v4.1.xsd">DataCite resource types</a>,
or the PARSE.Insight content-types from Re3data [[?RE3DATA-SCHEMA]].
</p>
<p>
In the following examples, a (notional) dataset is classified separately using values from different vocabularies.
</p>
<aside id="ex-dataset-type" class="example">
<pre class="nohighlight turtle">
:dataset-001
rdf:type dcat:Dataset ;
dcterms:type <http://purl.org/dc/dcmitype/Dataset> ;
.
:dataset-001
rdf:type dcat:Dataset ;
dcterms:type <http://id.loc.gov/vocabulary/marcgt/dtb> ;
.</pre>
</aside>
<p>
It is also possible for multiple classifications to be present in a single description.
</p>
<aside id="ex-dataset-multiple-types" class="example">
<pre class="nohighlight turtle">
:dataset-001
rdf:type dcat:Dataset ;
dcterms:type <http://purl.org/dc/dcmitype/Dataset> ;
dcterms:type <http://id.loc.gov/vocabulary/marcgt/dtb> ;
dcterms:type <http://registry.it.csiro.au/def/datacite/resourceType/Dataset> ;
dcterms:type <http://registry.it.csiro.au/def/re3data/contentType/database> ;
.
<http://registry.it.csiro.au/def/datacite/resourceType/Dataset>
rdfs:label "Dataset"@en ;
dcterms:source "DataCite resource types"@en ;
.
<http://registry.it.csiro.au/def/re3data/contentType/database>
rdfs:label "Database"@en ;
dcterms:source "Re3data content types"@en ;
.</pre>
</aside>
</section>
<section id="describing-catalog-records-metadata">
<h3>Describing catalog records metadata</h3>
<p>If the catalog publisher decides to keep metadata
describing its records (i.e. the records containing metadata
describing the datasets), <code>dcat:CatalogRecord</code> can be used. For example,
while <code>:dataset-001</code> was issued on 2011-12-05, its description on Imaginary Catalog was added on 2011-12-11. This can be represented by DCAT as in <a href="#ex-catalog-record"></a>:
</p>
<aside id="ex-catalog-record" class="example">
<pre class="nohighlight turtle">
:catalog dcat:record :record-001 .
:record-001
a dcat:CatalogRecord ;
foaf:primaryTopic :dataset-001 ;
dcterms:issued "2011-12-11"^^xsd:date ;
.</pre>
</aside>
</section>
<section id="example-landing-page">
<h3>Dataset available only behind some Web page</h3>
<p><code>:dataset-002</code> is available as a CSV file. However <code>:dataset-002</code> can only be obtained through some Web page
where the user needs to follow some links, provide some information and check some boxes
before accessing the data.</p>
<aside id="ex-landing-page" class="example">
<pre class="nohighlight turtle">
ex:dataset-002
a dcat:Dataset ;
dcat:landingPage <http://dcat.example.org/dataset-002.html> ;
dcat:distribution ex:dataset-002-csv ;
.
:dataset-002-csv
a dcat:Distribution ;
dcat:accessURL <http://dcat.example.org/dataset-002.html> ;
dcat:mediaType <http://www.iana.org/assignments/media-types/text/csv> ;
.</pre>
</aside>
<p>Notice the use of a <code>dcat:landingPage</code> and the definition of the <code>dcat:Distribution</code> instance.</p>
</section>
<section id="a-dataset-available-as-download-and-behind-some-web-page">
<h3>A dataset available as a download and behind some Web page</h3>
<p>On the other hand, <code>:dataset-003</code> can be obtained through some landing page but also can be downloaded from a known URL.
</p>
<aside id="ex-access-and-download-url" class="example">
<pre class="nohighlight turtle">
ex:dataset-003
a dcat:Dataset ;
dcat:landingPage <http://dcat.example.org/dataset-003.html> ;
dcat:distribution ex:dataset-003-csv ;
.
:dataset-003-csv
a dcat:Distribution ;
dcat:downloadURL <http://dcat.example.org/dataset-003.csv> ;
dcat:mediaType <http://www.iana.org/assignments/media-types/text/csv> ;
.</pre>
</aside>
<p>Notice that we used <code>dcat:downloadURL</code> with the downloadable distribution and that the other distribution accessible through the landing page
does not have to be defined as a separate <code>dcat:Distribution</code> instance.</p>
</section>
<section id="a-dataset-available-from-a-service">
<h3>A dataset available through a service</h3>
<p><code>:dataset-004</code> is distributed in different representations from different services.
The <code>dcat:accessURL</code> for each <code>dcat:Distribution</code> corresponds with the <code>dcat:endpointURL</code> of the service.
Each service is characterized by its general type using <code>dcterms:type</code> (here using values from the INSPIRE spatial data service type vocabulary),
its specific API definition using <code>dcterms:conformsTo</code>,
with the detailed description of the individual endpoint parameters and options linked using <code>dcat:endpointDescription</code>.
</p>
<aside id="ex-access-service" class="example">
<pre class="nohighlight turtle">
ex:dataset-004
rdf:type dcat:Dataset ;
dcat:distribution ex:dataset-004-csv ;
dcat:distribution ex:dataset-004-png ;
.
ex:dataset-004-csv
rdf:type dcat:Distribution ;
dcat:accessService ex:table-service-005 ;
dcat:accessURL <http://dcat.example.org/api/table-005> ;
dcat:mediaType <http://www.iana.org/assignments/media-types/text/csv> ;
.
ex:dataset-004-png
rdf:type dcat:Distribution ;
dcat:accessService ex:figure-service-006 ;
dcat:accessURL <http://dcat.example.org/api/figure-006> ;
dcat:mediaType <http://www.iana.org/assignments/media-types/image/png> ;
.
ex:figure-service-006
rdf:type dcat:DataService ;
dcterms:conformsTo <http://dcat.example.org/apidef/figure/v1.0> ;
dcterms:type <https://inspire.ec.europa.eu/metadata-codelist/SpatialDataServiceType/view> ;
dcat:endpointDescription <http://dcat.example.org/api/figure-006/params> ;
dcat:endpointURL <http://dcat.example.org/api/figure-006> ;
dcat:servesDataset ex:dataset-004 ;
.
ex:table-service-005
rdf:type dcat:DataService ;
dcterms:conformsTo <http://dcat.example.org/apidef/table/v2.2> ;
dcterms:type <https://inspire.ec.europa.eu/metadata-codelist/SpatialDataServiceType/download> ;
dcat:endpointDescription <http://dcat.example.org/api/table-005/capability> ;
dcat:endpointURL <http://dcat.example.org/api/table-005> ;
dcat:servesDataset ex:dataset-003, ex:dataset-004 ;
.</pre>
</aside>
</section>
</section>
<section id="vocabulary-specification">
<h2>Vocabulary specification</h2>
<section id="RDF-representation">
<h3>RDF representation</h3>
<!--NoBacklogNorCR div class="issue" data-number="65">
<p>
Guidance on the use DCAT in a weakly-axiomatized environment, such as schema.org, has been identified as a requirement to be satisfied in this revision of DCAT.
</p>
<p>
An <a href="https://w3c.github.io/dxwg/dcat/rdf/dcat-schema.ttl">RDF graph containing a proposed alignment of DCAT with schema.org</a> is available. Comments on this alignment are invited.
</p>
</div-->
<!--backlog p class="issue" data-number="105">
The use of guarded constraints (existence, cardinality, range-type) to control the use of the recommended properties in the context of a class is being considered as part of the revision of DCAT.
</p-->
<!--NoBacklogNorCR p class="issue" data-number="110">
The axiomatization of DCAT 1 used global domain and range constraints for many of the properties defined in the DCAT namespace [[?VOCAB-DCAT-20140116]]. This makes quite strong ontological commitments, some of which are now being reconsidered - see individual issues noted inline below.
</p-->
<aside class="ednote">
<p>New RDF serializations will be made available for DCAT 3 as soon as the vocabulary is finalized.</p>
</aside>
<p>The (revised) DCAT vocabulary is <a href="https://www.w3.org/ns/dcat#">available in RDF</a>.
The primary artefact <a href="https://www.w3.org/ns/dcat2.ttl"><code>dcat2.ttl</code></a> is a serialization of the core DCAT vocabulary.
Alongside it are a set of other RDF files that provide additional information, including:</p>
<ol>
<li>
non-normative alignments to other vocabularies, provided for guidance
</li>
<li>
additional axioms, which can be useful in some contexts
</li>
<li>
the files <a href="https://www.w3.org/ns/dcat2014.ttl">dcat2014.ttl</a> and <a href="https://www.w3.org/ns/dcat2014.rdf">dcat2014.rdf</a> that correspond to the 2014 version of DCAT [[?VOCAB-DCAT-20140116]]
</li>
</ol>
<!--NoBacklogNorCR p class="issue" data-number="144">
The implementation of a DCAT 1 profile of the revised DCAT is being considered.
</p -->
</section>
<section id="external-vocab">
<h3>Elements from other vocabularies</h3>
<p>
DCAT requires use of elements from a number of other vocabularies.
Furthermore, DCAT may be augmented by additional elements from external vocabularies, following the usual RDFS [[!RDF-SCHEMA]] and OWL2 [[!OWL2-OVERVIEW]] rules and patterns.
</p>
<section id="complements">
<h4>Complementary vocabularies</h4>
<p>
Elements from a number of complementary vocabularies MAY be used together with DCAT to provide more detailed information.
For example: properties from the VoID vocabulary [[?VOID]] allow the description of various statistics about a DCAT-described dataset if that dataset is in RDF format; properties from the Provenance ontology [[!PROV-O]] can be used to provide more information about the workflow that generated a dataset or service and related activities and agents; classes and properties from the Organization Ontology [[?VOCAB-ORG]] can be used to explain additional details of responsible agents.
</p>
</section>
<section id="dependencies">
<h4>Element definitions</h4>
<p>
The definitions (including domain and range) of terms outside the DCAT namespace are provided here only for convenience and MUST NOT be considered normative. The authoritative definitions of these terms are in the corresponding specifications, i.e. [[!DC11]], [[!DCTERMS]], [[!FOAF]], [[!PROV-O]], [[!RDF-SCHEMA]], [[!SKOS-REFERENCE]], [[!XMLSCHEMA11-2]] and [[?VCARD-RDF]].
</p>
</section>
</section>
<section id="Class:Catalog">
<h3>Class: Catalog</h3>
<aside class="note">
<p>The scope of <code>dcat:Catalog</code> in DCAT 1 was catalogs of datasets [[?VOCAB-DCAT-20140116]]. For DCAT 2, this was generalized, and properties common to all cataloged resources were associated with a super-class <a href="#Class:Resource"><code>dcat:Resource</code></a>.</p>
<p>Moreover, an explicit class for <a href="#Class:Data_Service">data services</a> was added in DCAT 2, to enable these to be part of a catalog.</p>
<p>Finally, <code>dcat:Catalog</code> was made a sub-class of <code>dcat:Dataset</code>, and provision for catalogs to be composed of other catalogs is also enabled.</p>
<p>See Issue <a href="https://github.com/w3c/dxwg/issues/116">#116</a> and Issue <a href="https://github.com/w3c/dxwg/issues/172">#172</a>.</p>
</aside>
<!--
<p>The following properties are specific to this class:
<a href="#Property:catalog_catalog_record">catalog record</a>,
<a href="#Property:catalog_has_part">has part</a>,
<a href="#Property:catalog_dataset">dataset</a>,
<a href="#Property:catalog_service">service</a>,
<a href="#Property:catalog_catalog">catalog</a>,
<a href="#Property:catalog_homepage">homepage</a>,
<a href="#Property:catalog_themes">themes</a>.
</p>
-->
<p>The following properties are specific to this class:<p>
<ul class="prop-list">
<li><a href="#Property:catalog_catalog_record">catalog record</a></li>
<!-- DCAT 2
<li><a href="#Property:catalog_has_part">has part</a></li>
-->
<li><a href="#Property:catalog_resource">resource</a></li>
<li><a href="#Property:catalog_dataset">dataset</a></li>
<li><a href="#Property:catalog_service">service</a></li>
<li><a href="#Property:catalog_catalog">catalog</a></li>
<li><a href="#Property:catalog_homepage">homepage</a></li>
<li><a href="#Property:catalog_themes">themes</a></li>
</ul>
<p>The following properties of the super-class <a href="#Class:Dataset"><code>dcat:Dataset</code></a> are also available for use:</p>
<ul class="prop-list">
<li><a href="#Property:dataset_distribution">distribution</a></li>
<li><a href="#Property:dataset_frequency">frequency</a></li>
<li><a href="#Property:dataset_spatial">spatial/geographic coverage</a></li>
<li><a href="#Property:dataset_spatial_resolution">spatial resolution</a></li>
<li><a href="#Property:dataset_temporal">temporal coverage</a></li>
<li><a href="#Property:dataset_temporal_resolution">temporal resolution</a></li>
<li><a href="#Property:dataset_was_generated_by">was generated by</a></li>
</ul>
<p>The following properties of the super-class <a href="#Class:Resource"><code>dcat:Resource</code></a> are also available for use:</p>
<ul class="prop-list">
<li><a href="#Property:resource_access_rights">access rights</a></li>
<li><a href="#Property:resource_conforms_to">conforms to</a></li>
<li><a href="#Property:resource_contact_point">contact point</a></li>
<li><a href="#Property:resource_creator">creator</a></li>
<li><a href="#Property:resource_description">description</a></li>
<li><a href="#Property:resource_has_policy">has policy</a></li>
<li><a href="#Property:resource_identifier">identifier</a></li>
<li><a href="#Property:resource_is_referenced_by">is referenced by</a></li>
<li><a href="#Property:resource_keyword">keyword/tag</a></li>
<li><a href="#Property:resource_landing_page">landing page</a></li>
<li><a href="#Property:resource_license">license</a></li>
<li><a href="#Property:resource_language">catalog language</a></li>
<li><a href="#Property:resource_relation">relation</a></li>
<li><a href="#Property:resource_rights">rights</a></li>
<li><a href="#Property:resource_qualified_relation">qualified relation</a></li>
<li><a href="#Property:resource_publisher">publisher</a></li>
<li><a href="#Property:resource_release_date">release date</a></li>
<li><a href="#Property:resource_theme">theme/category</a></li>
<li><a href="#Property:resource_title">title</a></li>
<li><a href="#Property:resource_type">type/genre</a></li>
<li><a href="#Property:resource_update_date">update/modification date</a></li>
<li><a href="#Property:resource_qualified_attribution">qualified attribution</a></li>
<li><a href="#Property:resource_has_current_version">has current version</a></li>
<!--
<li><a href="#Property:resource_has_last_version">has last version</a></li>
-->
<li><a href="#Property:resource_has_version">has version</a></li>
<!-- <li><a href="#Property:resource_is_replaced_by">is replaced by</a></li> -->
<!--
<li><a href="#Property:resource_is_version_of">is version of</a></li>
-->
<li><a href="#Property:resource_previous_version">previous version</a></li>
<li><a href="#Property:resource_replaces">replaces</a></li>
<li><a href="#Property:resource_status">status</a></li>
<li><a href="#Property:resource_version">version</a></li>
<li><a href="#Property:resource_version_notes">version notes</a></li>
<li><a href="#Property:resource_first">first</a></li>
<li><a href="#Property:resource_last">last</a></li>
<!-- <li><a href="#Property:resource_next">next</a></li> -->
<li><a href="#Property:resource_previous">previous</a></li>
</ul>
<table class="def">
<tr><th>RDF Class:</th><td><a href="http://www.w3.org/ns/dcat#Catalog"><code>dcat:Catalog</code></a></td></tr>
<tr><th class="prop">Definition:</th><td>A curated collection of metadata about resources.</td></tr>
<tr><th class="prop">Sub-class of:</th><td><a href="#Class:Dataset"><code>dcat:Dataset</code></a></td></tr>
<tr><th class="prop">Usage note:</th><td>A Web-based data catalog is typically represented as a single instance of this class.</td></tr>
<tr><th class="prop">Usage note:</th><td>Datasets and data services are examples of resources in the context of a data catalog.</td></tr>
<tr><th class="prop">See also:</th><td> <a href="#Class:Catalog_Record"></a>, <a href="#Class:Dataset"></a></td></tr>
</table>
<section id="Property:catalog_homepage">
<h4>Property: homepage</h4>
<table class="def">
<tr><th>RDF Property:</th><td><a href="http://xmlns.com/foaf/0.1/homepage"><code>foaf:homepage</code></a></td></tr>
<tr><th class="prop">Definition:</th><td>A homepage of the catalog (a public Web document usually available in HTML).</td></tr>
<tr><th class="prop">Range:</th><td><a href="http://xmlns.com/foaf/0.1/Document"><code>foaf:Document</code></a></td></tr>
<tr><th class="prop">Usage note:</th><td><a href="http://xmlns.com/foaf/0.1/homepage"><code>foaf:homepage</code></a> is an inverse functional property (IFP) which means that it MUST be unique and precisely identify the Web-page for the resource. This property indicates the canonical Web-page, which might be helpful in cases where there is more than one Web-page about the resource.</td></tr>
</table>
</section>
<section id="Property:catalog_themes">
<h4>Property: themes</h4>
<table class="def">
<tr><th>RDF Property:</th><td><a href="http://www.w3.org/ns/dcat#themeTaxonomy"><code>dcat:themeTaxonomy</code></a></td></tr>
<tr><th class="prop">Definition:</th><td>A knowledge organization system (KOS) used to classify the resources documented in the catalog (e.g., datasets and services).</td></tr>
<tr><th class="prop">Domain:</th><td><a href="#Class:Catalog"><code>dcat:Catalog</code></a></td></tr>
<tr><th class="prop">Range:</th><td><a href="http://www.w3.org/2000/01/rdf-schema#Resource"><code>rdfs:Resource</code></a></td></tr>
<tr>
<th class="prop">
Usage note:
</th>
<td>
It is recommended that the taxonomy is organized in a <a href="http://www.w3.org/2004/02/skos/core#ConceptScheme"><code>skos:ConceptScheme</code></a>, <a href="http://www.w3.org/2004/02/skos/core#Collection"><code>skos:Collection</code></a>, <a href="http://www.w3.org/2002/07/owl#Ontology"><code>owl:Ontology</code></a> or similar, which allows each member to be denoted by an IRI and published as Linked Data.
</td>
</tr>
</table>
</section>
<!-- DCAT2
<section id="Property:catalog_has_part">
<h4>Property: has part</h4>
<aside class="note">
<p>
Property added in this context in DCAT 2.
</p>
</aside>
-->
<section id="Property:catalog_resource">
<h4>Property: resource</h4>
<aside class="note">
<p>
Property added in this context in DCAT 3.
</p>
</aside>
<table class="def">
<!-- DCAT2
<tr><th>RDF Property:</th><td><a href="http://purl.org/dc/terms/hasPart"><code>dcterms:hasPart</code></a></td></tr>
-->
<tr><th>RDF Property:</th><td><a href="http://www.w3.org/ns/dcat#resource"><code>dcat:resource</code></a></td></tr>
<tr><th class="prop">Definition:</th><td>A resource that is listed in the catalog.</td></tr>
<tr><th class="prop">Sub-property of:</th><td><a href="http://purl.org/dc/terms/hasPart"><code>dcterms:hasPart</code></a></td></tr>
<tr><th class="prop">Domain:</th><td><a href="#Class:Catalog"><code>dcat:Catalog</code></a></td></tr>
<tr><th class="prop">Range:</th><td><a href="#Class:Resource"><code>dcat:Resource</code></a></td></tr>
<tr><th class="prop">Usage note:</th><td>This is the most general predicate for membership of a catalog. Use of a more specific sub-property is recommended when available. </td></tr>
<!-- DCAT2
<tr><th class="prop">See also:</th><td>Sub-properties of <code>dcterms:hasPart</code> in particular <a href="#Property:catalog_dataset"><code>dcat:dataset</code></a>, <a href="#Property:catalog_catalog"><code>dcat:catalog</code></a>, <a href="#Property:catalog_service"><code>dcat:service</code></a>. </td></tr>
-->
<tr><th class="prop">See also:</th><td>Sub-properties of <code>dcat:resource</code> in particular <a href="#Property:catalog_dataset"><code>dcat:dataset</code></a>, <a href="#Property:catalog_catalog"><code>dcat:catalog</code></a>, <a href="#Property:catalog_service"><code>dcat:service</code></a>. </td></tr>
</table>
</section>
<section id="Property:catalog_dataset">
<h4>Property: dataset</h4>
<table class="def">
<tr><th>RDF Property:</th><td><a href="http://www.w3.org/ns/dcat#dataset"><code>dcat:dataset</code></a></td></tr>
<tr><th class="prop">Definition:</th><td>A dataset that is listed in the catalog.</td></tr>
<!-- DCAT2
<tr><th class="prop">Sub-property of:</th><td><a href="http://purl.org/dc/terms/hasPart"><code>dcterms:hasPart</code></a></td></tr>
-->
<tr><th class="prop">Sub-property of:</th><td><a href="#Property:catalog_resource"><code>dcat:resource</code></a></td></tr>
<tr><th class="prop">Domain:</th><td><a href="#Class:Catalog"><code>dcat:Catalog</code></a></td></tr>
<tr><th class="prop">Range:</th><td><a href="#Class:Dataset"><code>dcat:Dataset</code></a></td></tr>
</table>
</section>
<section id="Property:catalog_service">
<h4>Property: service</h4>
<aside class="note">
<p>
Property added in DCAT 2.
</p>
</aside>
<table class="def">
<tr><th>RDF Property:</th><td><a href="http://www.w3.org/ns/dcat#service"><code>dcat:service</code></a></td></tr>
<tr><th class="prop">Definition:</th><td>A service that is listed in the catalog.</td></tr>
<!-- DCAT2
<tr><th class="prop">Sub-property of:</th><td><a href="http://purl.org/dc/terms/hasPart"><code>dcterms:hasPart</code></a></td></tr>
-->
<tr><th class="prop">Sub-property of:</th><td><a href="#Property:catalog_resource"><code>dcat:resource</code></a></td></tr>
<tr><th class="prop">Domain:</th><td><a href="#Class:Catalog"><code>dcat:Catalog</code></a></td></tr>
<tr><th class="prop">Range:</th><td><a href="#Class:Data_Service"><code>dcat:DataService</code></a></td></tr>
</table>
</section>
<section id="Property:catalog_catalog">
<h4>Property: catalog</h4>
<aside class="note">
<p>
Property added in DCAT 2.
</p>
</aside>
<table class="def">
<tr><th>RDF Property:</th><td><a href="http://www.w3.org/ns/dcat#catalog"><code>dcat:catalog</code></a></td></tr>
<tr><th class="prop">Definition:</th><td>A catalog that is listed in the catalog.</td></tr>
<!-- DCAT2
<tr><th class="prop">Sub-property of:</th><td><a href="http://purl.org/dc/terms/hasPart"><code>dcterms:hasPart</code></a></td></tr>
-->