diff --git a/index.html b/index.html
index 81f002e..a8ed6e8 100644
--- a/index.html
+++ b/index.html
@@ -214,6 +214,10 @@ <h2>Modifications to existing procedures</h2>
                   <var>answeredDirection</var> to represent the peer's point of
                   view.</p>
                 </li>
+                <li>
+                  <p>If this extension cannot be used because of other options
+                    negotiated in the answer, set <var>answeredDirection</var>
+                    to {{RTCRtpTransceiverDirection/"stopped"}}.</p>
                 <li>
                   <p>Set
                   <var>extension</var>.{{RTCRtpHeaderExtensionCapability/direction}}