--- a/dcat/index.html Thu Mar 07 22:39:33 2013 +0000
+++ b/dcat/index.html Fri Mar 08 01:46:25 2013 +0000
@@ -73,30 +73,6 @@
<p>This document does not prescribe any particular method of deploying data expressed in DCAT. DCAT is applicable in many contexts including RDF accessible via SPARQL endpoints, embedded in HTML pages as RDFa, or serialized as e.g. RDF/XML or Turtle. The examples in this document use Turtle simply because of Turtle's readability.</p>
</section>
-<section id="conformance">
-A data catalog conforms to DCAT if:
-<ul>
-<li> It is organized into datasets and distributions.</li>
-
-<li> An RDF description of the catalog itself and its datasets and distributions is available (but the choice of
-RDF syntaxes, access protocols, and access policies is 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 and its dataset and distributions, are included in this RDF description, 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>
-
-<li>DCAT-compliant catalogs MAY include additional non-DCAT metadata fields and additional RDF data in the catalog's RDF description.</li>
-</ul>
-
-A <strong>DCAT profile</strong> is a specification for data catalogs 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:
-<ul>
-<li> A minimum set of required metadata fields </li>
-<li> Classes and properties for additional metadata fields not covered in DCAT</li>
-<li> Controlled vocabularies or URI sets as acceptable values for properties</li>
-<li> Requirements for specific access mechanisms (RDF syntaxes, protocols) to the catalog's RDF description</li>
-</ul>
-
-</section>
<section>
<h2 id="ns">Namespaces</h2>
<p>The namespace for DCAT is <code>http://www.w3.org/ns/dcat#</code>. However,
@@ -131,22 +107,20 @@
<p><img alt="UML model of DCAT classes and properties" src="dcat-model.jpg"/></p>
-<h2 id="example">Example</h2>
+<section>
+<h2 id="example">Basic Example</h2>
<p>This example provides a quick overview of how dcat might be used to represent a government catalog and its datasets. </p>
-<p>@@@ TODO.jse: Illustrate more clearly how these "examples" might appear "in the wild." Esp. the use of skos:Concept (etc) in RDFa... @@@</p>
-
<p>First, the catalog description:
</p>
<pre> :catalog
a dcat:Catalog ;
dcterms:title "Imaginary catalog" ;
rdfs:label "Imaginary catalog" ;
- foaf:homepage <<a href="http://example.org/catalog" class="external free" title="http://example.org/catalog" rel="nofollow">http://example.org/catalog</a>> ;
+ foaf:homepage <http://example.org/catalog> ;
dcterms:publisher :transparency-office ;
- dcat:themeTaxonomy :themes ;
- dcterms:language "en"^^xsd:language ;
- dcat:dataset :dataset-001 ;
+ dcterms:language <http://id.loc.gov/vocabulary/iso639-1/en> ;
+ dcat:dataset :dataset-001 , :dataset-002 , dataset-003 ;
.
</pre>
<p>The publisher of the catalog has the relative URI :transparency-office. Further description of the publisher can be provided as in the following example:
@@ -156,13 +130,6 @@
rdfs:label "Transparency Office" ;
.
</pre>
-<p>The catalog classifies its datasets according to a set of domains represented by the relative URI :themes. SKOS can be used to describe the domains used:
-</p>
-<pre> :themes
- a skos:ConceptScheme ;
- skos:prefLabel "A set of domains to classify documents" ;
- .
-</pre>
<p>The catalog lists each of its datasets via dcat:dataset property. In the example above, an example dataset was mentioned with the relative URI :dataset-001. A possible description of it using dcat is shown below:
</p>
<pre> :dataset-001
@@ -178,14 +145,8 @@
dcat:Distribution :dataset-001-csv ;
.
</pre>
-<p>Notice that this dataset is classified under the domain represented by the relative URI :accountability. This should be part of the domains set identified by the URI :themes that was used to describe the catalog domains. An example SKOS description
-</p>
-<pre> :accountability
- a skos:Concept ;
- skos:inScheme :themes ;
- skos:prefLabel "Accountability" ;
- .
-</pre>
+
+
<p>The dataset can be downloaded as a 5Kb CSV file. This is
represented via the RDF resource of type dcat:Distribution :dataset-001-csv.
</p>
@@ -204,6 +165,33 @@
]
.
</pre>
+</section>
+
+<section>
+<h2 id="example-classification">Classifying datasets</h2>
+<p>The catalog classifies its datasets according to a set of domains represented by the relative URI :themes. SKOS can be used to describe the domains used:
+</p>
+<pre> :catalog dcat:themeTaxonomy :themes .
+</pre>
+
+<pre> :themes
+ a skos:ConceptScheme ;
+ skos:prefLabel "A set of domains to classify documents" ;
+ .
+</pre>
+
+<p>Notice that this dataset is classified under the domain represented by the relative URI :accountability. This should be part of the domains set identified by the URI :themes that was used to describe the catalog domains. An example SKOS description
+</p>
+<pre> :accountability
+ a skos:Concept ;
+ skos:inScheme :themes ;
+ skos:prefLabel "Accountability" ;
+ .
+</pre>
+</section>
+
+<section>
+<h2 id="example-catalog-record">Describing catalog records metadata</h2>
<p>Finally, if the catalog publisher decides to keep metadata
describing its records (i.e. the records containing metadata
describing the datasets) dcat:CatalogRecord can be used. For example,
@@ -218,13 +206,22 @@
dcat:record :record-001 ;
.
</pre>
-<a name="Encoding_of_property_values" id="Encoding_of_property_values"></a><h2> <span class="mw-headline"> Encoding of property values </span></h2>
-<ul><li> Values like "unknown" or "unspecified" should never be used, and if present in the original database should be filtered for publishing. Instead, the property should simply be omitted.
-</li><li> @@@ policy for using resources vs. literals
-</li></ul>
</section>
<section>
+<h2 id="">A dataset available only behind some Web page</h2>
+</section>
+
+<section>
+<h2 id="">A dataset available as download and behind some Web page</h2>
+</section>
+
+</section>
+
+<section>
+<h1 id="vocab-spec">Vocabulary specification</h1>
+
+<section>
<h2 id="Class:_Catalog">Class: Catalog</h2>
<p>A data catalog is a curated collection of metadata about datasets.</p>
<table class="definition">
@@ -262,7 +259,7 @@
</section>
<section>
-<h3 id="Property:_spatial.2Fgeographic_coverage">Property: spatial/geographic coverage></h3>
+<h3 id="Property:_spatial.2Fgeographic_coverage">Property: spatial/geographic </h3>
<p>The geographical area covered by the catalog.</p>
<table class="definition">
<thead><tr><th>RDF Property:</th><th><a href="http://purl.org/dc/terms/spatial">dcterms:spatial</a></th></tr></thead>
@@ -312,8 +309,14 @@
<table class="definition">
<thead><tr><th>RDF Property:</th><th><a href="http://purl.org/dc/terms/language">dct:language</a></th></tr></thead>
<tbody>
- <tr><td class="prop">Range:</td><td><a href="http://www.w3.org/2000/01/rdf-schema#Literal">rdfs:Literal</a> a string representing the code of the language as described in <a href="http://www.ietf.org/rfc/rfc3066.txt">http://www.ietf.org/rfc/rfc3066.txt</a></td></tr>
- <tr><td class="prop">Usage note:</td><td>Multiple values can be used. The publisher might also choose to describe the language on the dataset level (see <a href="#">dataset language</a>).</td></tr>
+ <tr><td class="prop">Range:</td><td>
+ <a href="http://www.w3.org/2000/01/rdf-schema#Resource">rdfs:Resource</a>
+ <br/>
+ Resources defined by the Library of Congress (<a href="http://id.loc.gov/vocabulary/iso639-1.html">1</a>,
+ <a href="http://id.loc.gov/vocabulary/iso639-2.html">2</a>) SHOULD be used
+ <br/>
+If a ISO 639-1 (two-letter) code is defined for language, then its corresponding IRI SHOULD be used; if no ISO 639-1 code is defined, then IRI corresponding to the ISO 639-2 (three-letter) code SHOULD be used.</td></tr>
+ <tr><td class="prop">Usage note:</td><td>Multiple values can be used. The publisher might also choose to describe the language on the dataset level (see <a href="#Property:_language_2">dataset language</a>).</td></tr>
</tbody>
</table>
</section>
@@ -325,7 +328,6 @@
<thead><tr><th>RDF Property:</th><th><a href="http://purl.org/dc/terms/license">dcterms:license</a></th></tr></thead>
<tbody>
<tr><td class="prop">Range:</td><td><a href="http://purl.org/dc/dcmitype/LicenseDocument">dctype:LicenseDocument</a></td></tr>
- <tr><td class="prop">Usage note:</td><td>To allow automatic analysis of datasets, it is important to use canonical identifiers for well-known licenses, see @@@void guide@@@ for a list.</td></tr>
<tr><td class="prop">See also:</td><td><a href="#" title="">dataset license</a></td></tr>
</tbody>
</table>
@@ -500,7 +502,6 @@
<thead><tr><th>RDF Property:</th><th><a href="http://purl.org/dc/terms/accrualPeriodicity">dcterms:accrualPeriodicity</a></th></tr></thead>
<tbody>
<tr><td class="prop">Range:</td><td><a href="http://purl.org/dc/terms/Frequency">dcterms:Frequency</a> (A rate at which something recurs)</td></tr>
- <tr><td class="prop">Usage note:</td><td>@@@ values should come from a controlled vocabulary i.e. predefined set of resources. It could use values like <a href="http://www.placetime.com/interval/gregorian/">placetime.com intervals</a></td></tr>
<tr><td class="prop">Domain:</td><td><a href="http://purl.org/dc/terms/Collection">dcterms:Collection</a> so, a Catalog must be a dcterms:Collection as well.</td></tr>
</tbody>
</table>
@@ -527,20 +528,18 @@
<thead><tr><th>RDF Property:</th><th><a href="http://purl.org/dc/terms/spatial">dcterms:spatial</a></th></tr></thead>
<tbody>
<tr><td class="prop">Range:</td><td><a href="http://purl.org/dc/terms/Location">dcterms:Location</a> (A spatial region or named place)</td></tr>
- <tr><td class="prop">Usage note:</td><td> @@@ controlled vocabulary. geonames???</td></tr>
</tbody>
</table>
</section>
<section>
<h3 id="Property:_temporal_coverage">Property: temporal coverage</h3>
-<p>@@@ The temporal period that the dataset covers.</p>
+<p>The temporal period that the dataset covers.</p>
<table class="definition">
<thead><tr><th>RDF Property:</th><th><a href="http://purl.org/dc/terms/temporal">dcterms:temporal</a></th></tr></thead>
<tbody>
<tr><td class="prop">Range:</td><td><a href="http://purl.org/dc/terms/PeriodOfTime">dcterms:PeriodOfTime</a> (An interval of time that is named or defined by its start and end dates)</td></tr>
- <tr><td class="prop">Usage note:</td><td> @@@ controlled vocabulary. <a href="http://www.placetime.com/">http://www.placetime.com/</a> might be an option???</td></tr>
</tbody>
</table>
</section>
@@ -552,66 +551,18 @@
<table class="definition">
<thead><tr><th>RDF Property:</th><th><a href="http://purl.org/dc/terms/language">dct:language</a></th></tr></thead>
<tbody>
- <tr><td class="prop">Range:</td><td><a href="http://www.w3.org/2000/01/rdf-schema#Literal">rdfs:Literal</a> a string representing the code of the language as described in <a href="http://www.ietf.org/rfc/rfc3066.txt">http://www.ietf.org/rfc/rfc3066.txt</a></td></tr>
+ <tr><td class="prop">Range:</td><td><a href="http://www.w3.org/2000/01/rdf-schema#Resource">rdfs:Resource</a>
+ <br/>
+ Resources defined by the Library of Congress (<a href="http://id.loc.gov/vocabulary/iso639-1.html">1</a>,
+ <a href="http://id.loc.gov/vocabulary/iso639-2.html">2</a>) SHOULD be used
+ <br/>
+If a ISO 639-1 (two-letter) code is defined for language, then its corresponding IRI SHOULD be used; if no ISO 639-1 code is defined, then IRI corresponding to the ISO 639-2 (three-letter) code SHOULD be used.</td></tr>
<tr><td class="prop">Usage note:</td><td>This overrides the value of the <a href="#Property:_language">catalog language</a> in case of conflict.</td></tr>
</tbody>
</table>
</section>
<section>
-<h3 id="Property:_license_2">Property: license</h3>
-<p>The license under which the dataset is published and can be reused.</p>
-
-<table class="definition">
- <thead><tr><th>RDF Property:</th><th><a href="http://purl.org/dc/terms/license">dcterms:license</a></th></tr></thead>
- <tbody>
- <tr><td class="prop">Range:</td><td><a href="http://purl.org/dc/dcmitype/LicenseDocument">dctype:LicenseDocument</a></td></tr>
- <tr><td class="prop">Usage note:</td><td>See <a href="http://www.w3.org/TR/void/#license">Section 2.4 of Describing Linked Datasets with the VoID Vocabulary</a>.</td></tr>
- </tbody>
-</table>
-</section>
-
-<section>
-<h3 id="Property:_granularity">Property: granularity</h3>
-<p>describes the level of granularity of data. @@@ elaborate more@@@</p>
-
-<table class="definition">
- <thead><tr><th>RDF Property:</th><th><a href="http://www.w3.org/ns/dcat#">dcat:granularity</a></th></tr></thead>
- <tbody>
- <tr><td class="prop">Range:</td><td><a href="http://www.w3.org/2000/01/rdf-schema#Resource">rdfs:Resource</a></td></tr>
- <tr><td class="prop">Usage note:</td><td>This is usually geographical or temporal but can also be other dimension e.g. Person can be used to describe granularity of a dataset about average income.</td></tr>
- </tbody>
-</table>
-<p>A set of sample values used in data.gov: country, county, longitude/latitude, region, plane, airport.</p>
-</section>
-
-<section>
-<h3 id="Property:_data_dictionary">Property: data dictionary</h3>
-<p>provides some sort of description that helps understanding the data. This usually consisits of a table providing explanation of columns meaning, values interpretation and acronyms/codes used in the data.</p>
-
-<table class="definition">
- <thead><tr><th>RDF Property:</th><th><a href="http://www.w3.org/ns/dcat#dataDictionary">dcat:dataDictionary</a></th></tr></thead>
- <tbody>
- <tr><td class="prop">Range:</td><td><a href="http://xmlns.com/foaf/0.1/Document">foaf:Document</a></td></tr>
- <tr><td class="prop">Usage note:</td><td>@@@ Review @@@ It is rarely provided in the current catalogs and does not have a consistent usage, however when it is provided it is a link to some document or embeded in a document packaged together with the dataset. It is recommended to represent it as a resource having the URL of the online document as its URI. Statistical datasets, as a particular yet common case, can have a more structured description and the on-progress work on <a href="http://groups.google.com/group/publishing-statistical-data">SDMX+RDF</a> can be utilized here.</td></tr>
- </tbody>
-</table>
-</section>
-
-<section>
-<h3 id="Property:_data_quality">Property: data quality</h3>
-<p>describes the quality of data.</p>
-
-<table class="definition">
- <thead><tr><th>RDF Property:</th><th><a href="http://www.w3.org/ns/dcat#dataQuality">dcat:dataQuality</a></th></tr></thead>
- <tbody>
- <tr><td class="prop">Range:</td><td><a href="http://www.w3.org/2000/01/rdf-schema#Literal">rdfs:Literal</a></td></tr>
- <tr><td class="prop">Usage note:</td><td>@@@Review@@@ This is a very general property and it is not clear how exactly it will be used as catalogs currently do not use it or use it with meaningless values. Catalogs are expected to define more specific sub-properties to describe quality characteristics e.g. statistical data usually have a lot to describe about the quality of sampling, collection mode, non-response adjustment…</td></tr>
- </tbody>
-</table>
-</section>
-
-<section>
<h3 id="Property:_theme.2Fcategory">Property: theme/category</h3>
<p>The main category of the dataset. A dataset can have multiple themes.</p>
@@ -637,19 +588,6 @@
</section>
<section>
-<h3 id="Property:_related_documents">Property: related documents</h3>
-<p>A related document such as technical documentation, agency program page, citation, etc.</p>
-
-<table class="definition">
- <thead><tr><th>RDF Property:</th><th><a href="http://purl.org/dc/terms/references">dcterms:references</a></th></tr></thead>
- <tbody>
- <tr><td class="prop">Range:</td><td>Has no defined range</td></tr>
- <tr><td class="prop">Usage note:</td><td>The value is the URI of the related document.</td></tr>
- </tbody>
-</table>
-</section>
-
-<section>
<h3 id="Property:_dataset_distribution">Property: dataset distribution</h3>
<p>Connects a dataset to its available distributions.</p>
<table class="definition">
@@ -675,6 +613,53 @@
</table>
<section>
+<h3 id="Property:_title_3">Property: title</h3>
+<p>A name given to the distribution.</p>
+
+<table class="definition">
+ <thead><tr><th>RDF Property:</th><th><a href="http://purl.org/dc/terms/title">dcterms:title</a></th></tr></thead>
+ <tbody>
+ <tr><td class="prop">Range:</td><td><a href="http://www.w3.org/2000/01/rdf-schema#Literal">rdfs:Literal</a></td></tr>
+ </tbody>
+</table>
+</section>
+
+<section>
+<h3 id="Property:_description_3">Property: description</h3>
+<p>free-text account of the distribution.</p>
+<table class="definition">
+ <thead><tr><th>RDF Property:</th><th><a href="http://purl.org/dc/terms/description">dcterms:description</a></th></tr></thead>
+ <tbody>
+ <tr><td class="prop">Range:</td><td><a href="http://www.w3.org/2000/01/rdf-schema#Literal">rdfs:Literal</a></td></tr>
+ </tbody>
+</table>
+</section>
+
+<section>
+<h3 id="Property:_release_date_2">Property: release date</h3>
+<p>Date of formal issuance (e.g., publication) of the distribution.</p>
+<table class="definition">
+ <thead><tr><th>RDF Property:</th><th><a href="http://purl.org/dc/terms/issued">dcterms:issued</a></th></tr></thead>
+ <tbody>
+ <tr><td class="prop">Range:</td><td><a href="http://www.w3.org/2000/01/rdf-schema#Literal">rdfs:Literal</a> typed as <a href="http://www.w3.org/TR/xmlschema-2/#date">xsd:date</a>. The date is encoded as a literal in "YYYY-MM-DD" form (<a href="http://www.w3.org/TR/NOTE-datetime">ISO 8601 Date and Time Formats</a>). If the specific day or month are not known, then 01 should be specified.</td></tr>
+ <tr><td class="prop">Usage note:</td><td>This property should be set using the first known date of issuance.</td></tr>
+ </tbody>
+</table>
+</section>
+
+<section>
+<h3 id="Property:_update.3Fmodification_date">Property: update/modification date</h3>
+<p>Most recent date on which the distribution was changed, updated or modified.</p>
+<table class="definition">
+ <thead><tr><th>RDF Property:</th><th><a href="http://purl.org/dc/terms/modified">dcterms:modified</a></th></tr></thead>
+ <tbody>
+ <tr><td class="prop">Range:</td><td><a href="http://www.w3.org/2000/01/rdf-schema#Literal">rdfs:Literal</a> typed as <a href="http://www.w3.org/TR/xmlschema-2/#date">xsd:date</a>. The date is encoded as a literal in "YYYY-MM-DD" form (<a href="http://www.w3.org/TR/NOTE-datetime">ISO 8601 Date and Time Formats</a>). If the specific day or month are not known, then 01 should be specified.</td></tr
+ <tr><td class="prop">See also:</td><td><a href="#" title=""> dataset modification date</a></td></tr>
+ </tbody>
+</table>
+</section>
+
+<section>
<h3 id="Property:_access.2Fdownload">Property: access/download</h3>
<p>points to the location of a distribution. This can be a direct download link, a link to an HTML page containing a link to the actual data, Feed, Web Service etc. the semantic is determined by its domain (Distribution, Feed, WebService, Download).</p>
<p class="issue">If the value is always a URI, shouldn't the range be rdfs:Resource?</p>
@@ -688,17 +673,42 @@
</table>
</section>
+<section>
+<h3 id="Property:_license_2">Property: license</h3>
+<p>The license under which the distribution is made available.</p>
+
+<table class="definition">
+ <thead><tr><th>RDF Property:</th><th><a href="http://purl.org/dc/terms/license">dcterms:license</a></th></tr></thead>
+ <tbody>
+ <tr><td class="prop">Range:</td><td><a href="http://purl.org/dc/dcmitype/LicenseDocument">dctype:LicenseDocument</a></td></tr>
+ </tbody>
+</table>
+</section>
+
<section>
-<h3 id="Property:_size">Property: size</h3>
-<p>The size of a distribution.</p>
+<h3 id="Property:_size">Property: byteSize</h3>
+<p>The size of a distribution in bytes.</p>
<table class="definition">
- <thead><tr><th>RDF Property:</th><th><a href="http://www.w3.org/ns/dcat#size">dcat:size</a></th></tr></thead>
+ <thead><tr><th>RDF Property:</th><th><a href="http://www.w3.org/ns/dcat#size">dcat:byteSize</a></th></tr></thead>
<tbody>
- <tr><td class="prop">Range:</td><td><a href="http://www.w3.org/2000/01/rdf-schema#Resource">rdfs:Resource</a></td></tr>
- <tr><td class="prop">Usage note:</td><td><a href="http://www.w3.org/ns/dcat#size">dcat:size</a> is usually used with a blank node described using <a href="http://www.w3.org/2000/01/rdf-schema#label">rdfs:label</a> and <a href="#Property:_bytes">dcat:bytes</a>.</td></tr>
- <tr><td class="prop">Example:</td><td><pre> :distribution dcat:size [dcat:bytes 5120^^xsd:integer; rdfs:label "5KB"]</pre></td></tr>
+ <tr><td class="prop">Range:</td><td><a href="http://www.w3.org/2000/01/rdf-schema#Literal">rdfs:Literal</a> typed as <a href="http://www.w3.org/TR/xmlschema-2/#decimal">xsd:decimal</a>.</td></tr>
+ <tr><td class="prop">Usage note:</td><td>The size in bytes can be approximated when the precise size is not known.</td></tr>
+ </tbody>
+</table>
+</section>
+
+<section>
+<h3 id="Property:_media_format">Property: media type</h3>
+<p>the media type of the distribution as defined by <a href="http://www.iana.org/assignments/media-types/">IANA</a>.</p>
+
+<table class="definition">
+ <thead><tr><th>RDF Property:</th><th><a href="http://www.w3.org/ns/dcat#mediaType">dcat:mediaType</a></th></tr></thead>
+ <tbody>
+ <tr><td class="prop">Sub property of:</td><td><a href="http://purl.org/dc/terms/format">dcterms:format</a></td></tr>
+ <tr><td class="prop">Range:</td><td><a href="http://purl.org/dc/terms/MediaTypeOrExtent">dcterms:MediaTypeOrExtent</a></td></tr>
+ <tr><td class="prop">Usage note:</td><td>This property SHOULD be used when the media type of the distribution is defined in <a href="http://www.iana.org/assignments/media-types/">IANA</a>, otherwise dcterms:format MAY be used with different values.</td></tr>
</tbody>
</table>
</section>
@@ -711,61 +721,12 @@
<thead><tr><th>RDF Property:</th><th><a href="http://purl.org/dc/terms/format">dcterms:format</a></th></tr></thead>
<tbody>
<tr><td class="prop">Range:</td><td><a href="http://purl.org/dc/terms/MediaTypeOrExtent">dcterms:MediaTypeOrExtent</a></td></tr>
- <tr><td class="prop">Usage note:</td><td>MIME type is used for values. A list of MIME types URLs can be found at <a href="http://www.iana.org/assignments/media-types/">IANA</a>. However ESRI Shape files have no specific MIME type (A Shape distribution is actually a collection of files), currently this is still an open question? @@@.</td></tr>
- <tr><td class="prop">Example:</td><td>
-<pre>:distribution dcterms:format [
- a dcterms:IMT;
- rdf:value "text/csv";
- rdfs:label "CSV"
-]</pre></td></tr>
+ <tr><td class="prop">Usage note:</td><td>dcat:mediaType SHOULD be used if the type of the distribution is defined at <a href="http://www.iana.org/assignments/media-types/">IANA</a>.</td></tr>
</tbody>
</table>
</section>
</section> <!-- end class Distribution -->
-
-<section>
-<h2 id="Class:_Download">Class: Download</h2>
-<p>Represents a downloadable distribution of a dataset.</p>
-
-<table class="definition">
- <thead><tr><th>RDF Class:</th><th><a href="http://www.w3.org/ns/dcat#Download">dcat:Download</a></th></tr></thead>
- <tbody>
- <tr><td class="prop">Sub class of:</td><td><a href="#Class:_Distribution">dcat:Distribution</a></td></tr>
- <tr><td class="prop">Usage note:</td><td><a href="#Property:_access.2Fdownload"> accessUrl</a> of the Download distribution should be a <strong>direct download link</strong> (a one-click access to the data file).</a></td></tr>
- <tr><td class="prop">See also:</td><td><a href="#Class:_Distribution">Distribution</a>, <a href="#Class:_WebService">WebService</a>, <a href="#Class:_Feed">Feed</a></td></tr>
- </tbody>
-</table>
-</section>
-
-<section>
-<h2 id="Class:_WebService">Class: WebService</h2>
-<p>Represents a web service that enables access to the data of a dataset.</p>
-
-<table class="definition">
- <thead><tr><th>RDF Class:</th><th><a href="http://www.w3.org/ns/dcat#WebService">dcat:WebService</a></th></tr></thead>
- <tbody>
- <tr><td class="prop">Sub class of:</td><td><a href="#Class:_Distribution">dcat:Distribution</a></td></tr>
- <tr><td class="prop">Usage note:</td><td>Describe the web service using <a href="#Property:_access.2Fdownload"> accessUrl</a>, <a href="#Property:_format"> format</a> and <a href="#Property:_size"> size</a>. Further description of the web service is out the scope of dcat.</td></tr>
- <tr><td class="prop">See also:</td><td><a href="#Class:_Distribution">Distribution</a>, <a href="#Class:_Download">Download</a>, <a href="#Class:_Feed">Feed</a></td></tr>
- </tbody>
-</table>
-</section>
-
-<section>
-<h2 id="Class:_Feed">Class: Feed</h2>
-<p>represent availability of a dataset as a feed.</p>
-
-<table class="definition">
- <thead><tr><th>RDF Class:</th><th><a href="http://www.w3.org/ns/dcat#Feed">dcat:Feed</a></th></tr></thead>
- <tbody>
- <tr><td class="prop">Sub class of:</td><td><a href="#Class:_Distribution">dcat:Distribution</a></td></tr>
- <tr><td class="prop">Usage note:</td><td>Describe the feed using <a href="#Property:_access.2Fdownload"> accessUrl</a>, <a href="#Property:_format">format</a> and <a href="#Property:_size"> size</a>. Further description of the web service is out the scope of dcat.</td></tr>
- <tr><td class="prop">See also:</td><td><a href="#Class:_Distribution">Distribution</a>, <a href="#Class:_Download">Download</a>, <a href="#Class:_WebService">WebService</a></td></tr>
- </tbody>
-</table>
-</section>
-
<section>
<h2 id="Class:_Category_and_category_scheme">Class: Category and category scheme</h2>
<p>The knowledge organization system (KOS) used to represent themes/categories of datasets in the catalog.</p>
@@ -790,20 +751,31 @@
</table>
</section>
-<section>
-<h2 id="Property:_bytes">Property: size in bytes</h2>
-<table class="definition">
- <thead><tr><th>RDF Property:</th><th><a href="http://www.w3.org/ns/dcat#bytes">dcat:bytes</a></th></tr></thead>
- <tbody>
- <tr><td class="prop">Range:</td><td><a href="http://www.w3.org/2000/01/rdf-schema#Literal">rdfs:Literal</a> typed as <a href="http://www.w3.org/TR/xmlschema-2/#int">xsd:int</a></td></tr>
- <tr><td class="prop">Usage note:</td><td>discribes a size of a
- distribution in bytes. <a href="#Property:_size">dcat:size</a> describes the size of a
- distribution by linking it to a resource that can have a string
- label and a the precise number of bytes stated by dcat:bytes.</td></tr>
-<tr><td class="prop">Example:</td><td><pre> :distribution dcat:size [dcat:bytes 5120^^xsd:integer; rdfs:label "5KB"]</pre></td></tr>
- </tbody>
-</table>
+</section>
+
+<section id="conformance">
+A data catalog conforms to DCAT if:
+<ul>
+<li> It is organized into datasets and distributions.</li>
+
+<li> An RDF description of the catalog itself and its datasets and distributions is available (but the choice of
+RDF syntaxes, access protocols, and access policies is 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 and its dataset and distributions, are included in this RDF description, 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>
+
+<li>DCAT-compliant catalogs MAY include additional non-DCAT metadata fields and additional RDF data in the catalog's RDF description.</li>
+</ul>
+
+A <strong>DCAT profile</strong> is a specification for data catalogs 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:
+<ul>
+<li> A minimum set of required metadata fields </li>
+<li> Classes and properties for additional metadata fields not covered in DCAT</li>
+<li> Controlled vocabularies or URI sets as acceptable values for properties</li>
+<li> Requirements for specific access mechanisms (RDF syntaxes, protocols) to the catalog's RDF description</li>
+</ul>
</section>