diff --git a/spec.html b/spec.html
index 817428f..0a4727b 100644
--- a/spec.html
+++ b/spec.html
@@ -5690,6 +5690,10 @@ <h3>Operator Dictionary</h3>
           (<code>Content</code>, <code>Form</code>) is as folllows:
         </p>
         <ol class=algorithm>
+          <li>
+            If <code>Content</code> as an UTF-16 string has length
+            0, then exit with category <code>K</code>.
+          </li>
           <li>
             If <code>Content</code> as an UTF-16 string does not have length
             or 1 or 2 then exit with category <code>Default</code>.