Apply suggestions from code review

Co-authored-by: Olaf Hartig <[email protected]>

Author: afs

spec/index.html

@@ -1022,9 +1022,9 @@ <h2>RDF Datasets</h2>
 
     <p>SPARQL 1.2 [[SPARQL12-QUERY]] uses 
       <a data-cite="SPARQL12-QUERY#sparqlDataset">the same concept of an RDF Dataset</a>
-      where an RDF Graph can be identified using an IRI or a blank node.
-      SPARQL 1.1 Query Language [[SPARQL12-QUERY]]
-      only allows RDF Graphs to be identified using an IRI.</p>
+      in which the graph names of named graphs may be IRIs or blank nodes.
+      In contrast, version 1.1 of the SPARQL Query Language [[SPARQL11-QUERY]]
+      only allows IRIs as graph names.</p>
 
   </div>