Update documentation
diff --git a/org.jacoco.doc/docroot/doc/agent.html b/org.jacoco.doc/docroot/doc/agent.html
index 5391c2e..c3dec5f 100644
--- a/org.jacoco.doc/docroot/doc/agent.html
+++ b/org.jacoco.doc/docroot/doc/agent.html
@@ -145,6 +145,7 @@
           <li><code>tcpclient</code>: At startup the agent connects to the TCP
               port specified by the <code>address</code> and <code>port</code>
               attribute. Execution data is written to this TCP connection.</li>
+          <li><code>none</code>: Do not produce any output.</li>
         </ul>
         Please see the security considerations below. 
       </td>