--- a/rdf-concepts/index.html	Sun Nov 20 19:54:26 2011 +0000
+++ b/rdf-concepts/index.html	Sun Nov 20 20:04:22 2011 +0000
@@ -979,9 +979,9 @@
 
     <p>A <dfn>datatype map</dfn> is an implementation-defined set of
     &lt;<a>IRI</a>, <a>datatype</a>&gt; pairs such that no
-    IRI appears twice in the set. It can be seen as a function from IRIs
-    to datatypes. It may only contain pairs in which the IRI denotes
-    the datatype. Every datatype map contains the pair
+    IRI appears twice in the set and the IRI denotes the datatype.
+    It can be seen as a function from IRIs
+    to datatypes. Every datatype map contains the pair
     &lt;<code>http://www.w3.org/1999/02/22-rdf-syntax-ns#XMLLiteral</code>,
     <code><a>rdf:XMLLiteral</a></code>&gt;.</p>