Remove untestable normative statement around issuer value.

index.html

@@ -1754,8 +1754,8 @@ <h3>Issuer</h3>
           <dd>
 The value of the <code>issuer</code> <a>property</a> MUST either be a
 <a>URL</a>, or be an object containing an <code>id</code> <a>property</a>
-whose value is a <a>URL</a>; in either case, the issuer MUST select this
-<a>URL</a> to identify the issuer in a globally unambiguous
+whose value is a <a>URL</a>; in either case, the issuer selects this
+<a>URL</a> to identify itself in a globally unambiguous
 way. It is RECOMMENDED that the <a>URL</a> be one which, if dereferenced,
 results in a document containing machine-readable information about the
 <a>issuer</a> that can be used to <a>verify</a> the information expressed in the