--- a/RelaxNG/publidoc.rng	ven. oct. 07 16:19:44 2011 +0200
+++ b/RelaxNG/publidoc.rng	dim. oct. 23 16:45:12 2011 +0200
@@ -975,12 +975,20 @@
   </define>
   <define name="image.attributes">
     <ref name="media.id.attribute"/>
+    <optional>
+      <ref name="image.type"/>
+    </optional>
   </define>
   <define name="media.id.attribute">
     <attribute name="id">
       <data type="NMTOKEN"/>
     </attribute>
   </define>
+  <define name="image.type">
+    <attribute name="type">
+      <value>thumbnail</value>
+    </attribute>
+  </define>
   <define name="image.content">
     <optional>
       <ref name="copyright"/>