fixed a small error, daniel
diff --git a/doc/xml.html b/doc/xml.html
index c33f1d2..03d0dae 100644
--- a/doc/xml.html
+++ b/doc/xml.html
@@ -1514,7 +1514,7 @@
content are done in a single declaration. Similary the following declares
<code>div1</code> elements:</p>
-<p><code><!ELEMENT div1 (head, (p | list | note)*, div2*)></code></p>
+<p><code><!ELEMENT div1 (head, (p | list | note)*, div2?)></code></p>
<p>means div1 contains one <code>head</code> then a series of optional
<code>p</code>, <code>list</code>s and <code>note</code>s and then an