pnames actually satisfy the IRI grammar

Author: pchampin

spec/index.html

@@ -303,7 +303,7 @@ <h3>RDF Vocabularies and Namespace IRIs</h3>
       <code>http://www.w3.org/1999/02/22-rdf-syntax-ns#XMLLiteral</code>
       would be abbreviated as <code>rdf:XMLLiteral</code>
       with the prefix mapping from <a href="#tab-vocab-ns"></a>.
-      Note however that these abbreviations are <em>not</em> valid IRIs,
+      Note however that these abbreviations are <em>not</em> valid IRIs (or only coincidentally),
       and must not be used in contexts where IRIs are expected.
       Namespace IRIs and namespace prefixes are <em>not</em> a formal part of the
       RDF data model. They are merely a syntactic convenience for