diff --git a/doc/ref.xml b/doc/ref.xml
index 3af0e8e..f936ac4 100644
--- a/doc/ref.xml
+++ b/doc/ref.xml
@@ -1,3 +1,9 @@
+<!--
+Copyright 2005-2006 Daniel James.
+Distributed under the Boost Software License, Version 1.0. (See accompanying
+file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+-->
+
 <library-reference>
   <section id="hash.reference.specification">
     <para>For the full specification, see section 6.3 of the