Update Example 21 to show how to use DCAT2

bp/index.html

@@ -1802,7 +1802,7 @@ <h4 class="subhead">Possible Approach to Implementation</h4>
 <p>Moreover, the original GeoJSON datatype URI used in the example (corresponding to <a href="https://www.iana.org/assignments/media-types/application/geo+json">the GeoJSON IANA Media Type URL</a>) has been replaced with <code>geosparql:geoJSONLiteral</code>, included in the draft of the new version of [[GeoSPARQL]] (see issues <a href="https://github.com/opengeospatial/ogc-geosparql/issues/1">opengeospatial/ogc-geosparql/issues/1</a> and  <a href="https://github.com/opengeospatial/ogc-geosparql/issues/48">opengeospatial/ogc-geosparql/issues/48</a>), already adopted in [[GeoDCAT-AP]].</p>
 </aside>
 
-            <p>The following [[TURTLE]] snippet shows the [[GeoDCAT-AP]] representation of the dataset in <a href="#ex-schemaorg-dataset-and-place"></a>. Here the bounding box is provided in multiple literal encodings (<a>WKT</a>, [[GML]], GeoJSON [[RFC7946]]), by using property <code>dcat:bbox</code> [[VOCAB-DCAT]].</p>
+            <p>The following [[TURTLE]] snippet shows the [[GeoDCAT-AP]] representation of the dataset in <a href="#ex-schemaorg-dataset-and-place"></a>. Here the bounding box is provided in multiple literal encodings (<a>WKT</a>, [[GML]], GeoJSON [[RFC7946]]), by using property <a href="https://www.w3.org/TR/vocab-dcat-2/#Property:location_bbox"><<code>dcat:bbox</code></a> [[VOCAB-DCAT]].</p>
             <aside class="example" id="ex-geodcat-ap-bag-addresses" title="[GeoDCAT-AP] representation of dataset spatial coverage (bounding box) in multiple encodings">
               <pre>
 @prefix dcat:      &lt;http://www.w3.org/ns/dcat#&gt; .
@@ -2092,9 +2092,40 @@ <h4 class="subhead">Possible Approach to Implementation</h4>
 
 # Bounding box
 
-  georss:box "52.3749,4.8838 52.3753,4.8845"^^xsd:string .
+  georss:box "52.3749,4.8838 52.3753,4.8845"^^xsd:string ;
 .
 </pre>
+
+<aside class="ednote">
+<p>Added the following example on the use of [[VOCAB-DCAT]] for the specification of centroids and bounding boxes.</p>
+</aside>
+
+<p>The same example can be written as follows, using the relevant properties from [[VOCAB-DCAT]] (<a href="https://www.w3.org/TR/vocab-dcat-2/#Property:location_centroid"><code>dcat:centroid</code></a> and <a href="https://www.w3.org/TR/vocab-dcat-2/#Property:location_bbox"><code>dcat:bbox</code></a>):</p>
+<pre>
+@prefix bag:       &lt;http://bag.basisregistraties.overheid.nl/def/bag#&gt; .
+@prefix dcat:      &lt;http://www.w3.org/ns/dcat#&gt; .
+@prefix geosparql: &lt;http://www.opengis.net/ont/geosparql#&gt; .
+@prefix rdfs:      &lt;http://www.w3.org/2000/01/rdf-schema#&gt; .
+
+&lt;http://bag.basisregistraties.overheid.nl/bag/id/pand/0363100012169587&gt; 
+  a geosparql:Feature, bag:Pand ;
+  rdfs:label "Pand 0363100012169587"@nl;
+
+# Detailed geometry  
+
+  ... 
+
+# Centroid
+
+  dcat:centroid "POINT(4.88412 52.37509)"^^geosparql:wktLiteral ;
+
+# Bounding box
+
+  dcat:bbox "POLYGON((4.8838 52.3749,4.8838 52.3753,4.8845 52.3753,
+             4.8845 52.3749,4.8838 52.3749))"^^geosparql:wktLiteral ;
+.
+</pre>
+
 </aside>
 </li>
 </ol>