Apply suggestion from @hartig

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

Author: afs

spec/index.html

@@ -1024,7 +1024,7 @@ <h4>RDF Reference IRIs</h4>
         This section provides advice to data publishers.
       </p>
       <p>
-        <a>IRIs</a> are used to denote <a>resources</a> and should identify the same
+        <a>IRIs</a> are used to denote <a>resources</a>, and each IRI should identify the same
         resource regardless of where the IRI reference is used.
         [[RFC3987]] defines a syntax that can express
         IRIs which do not meet the requirement of being a global reference.