--- a/spec/index.html	Thu Aug 08 17:08:23 2013 +0200
+++ b/spec/index.html	Fri Aug 09 08:27:40 2013 +0200
@@ -59,6 +59,9 @@
   <dd>This specification outlines a simple universal identification mechanism that is distributed, openly extensible, enabling each person to control their identity, and to build a decentralised web of trust, which can be used to allow fine grained access control. It does this by applying the best practices of Web Architecture whilst building on well established widely deployed protocols and standards including HTML, URIs, HTTP, and RDF Semantics.</dd>
   <dt><a href="tls-respec.html">WebID-TLS - WebID Authentication over TLS</a></dt>
   <dd> The WebID-TLS protocol enables secure, efficient and  user friendly authentication on the Web using TLS and X.509 Certificates. It enables people to authenticate onto any site by simply choosing one of the certificates proposed to them by their browser. These certificates can be created by any Web Site for their users. It is also very effective means for software agents to authenticate. This specification extends the WebID Identity specification which defines many of the core concepts used in WebID-TLS. </dd>
+  <dt><a href="http://www.w3.org/ns/auth/cert#">Certificate Ontology</a></dt>
+  <dd>WebID Profile documents can be used to publish public keys that identify the referent of the WebID as the owner of the corresponding private key. The Certificate Ontology defines the vocabulary to use to publish this information.
+  </dd>
 </dl>
 </section>