--- a/RelaxNG/publidoc.rng	ven. janv. 06 12:09:03 2012 +0100
+++ b/RelaxNG/publidoc.rng	sam. janv. 07 12:21:10 2012 +0100
@@ -576,6 +576,9 @@
       <optional>
         <ref name="topic.type.attribute"/>
       </optional>
+      <optional>
+        <ref name="lang.attribute"/>
+      </optional>
     </interleave>
   </define>
   <define name="topic.content">