diff --git a/spec/shadow/index.html b/spec/shadow/index.html
index 80880528..153cfeb3 100644
--- a/spec/shadow/index.html
+++ b/spec/shadow/index.html
@@ -289,6 +289,16 @@ <h3>Slots</h3>
           <li>The <a>root</a> <a>node</a> of the <a>slot element</a> is a <a>shadow root</a></li>
           <li>There is no other <a>slot element</a> in the <a lt="ancestor">ancestors</a> of the <a>slot element</a></li>
         </ul>
+
+        <p>
+          A <dfn>slot name</dfn> is the name of a <a>slot</a>.
+        </p>
+
+        <p>
+          A <dfn>default slot</dfn> is a slot that doesn't have a <a>slot name</a>.
+          If there are more than one slots which doen't have a <a>slot name</a> in the same <a>shadow tree</a>, the most <a>preceding</a> one is the <a>default slot</a>. The others are not.
+        </p>
+
       </section>
 
       <section>
@@ -1399,7 +1409,7 @@ <h3>The <code>slot</code> element</h3>
           <dd><a>Global attributes</a></dd>
           <dd>
             <dl>
-              <dt><code><dfn lt="slot name">name</dfn></code>, the name of the slot</dt>
+              <dt><code>name</dfn></code>, the <a>slot name</a></dt>
               <dd>Represents the <a>slot name</a>.</dd>
             </dl>
           </dd>