All claims we list as possible in an Entity Statement should be listed in section 3.

Author: rohe

openid-federation-1_0.xml

@@ -732,6 +732,13 @@
 	      location can be determined by retrieving
 	      the Entity Configuration of the issuer.
             </t>
+            <t hangText="trust_anchor">
+              <vspace/>
+              OPTIONAL.  Its value MUST be the Entity Identifier of the Trust Anchor
+                that the OP selected to process the Explicit Registration request.
+                This claim is specific to Explicit Registration responses and is not a
+                general Entity Statement claim.
+            </t>
           </list>
         </t>
         <t>