--- a/RelaxNG/publidoc.rnc	mar. juin 04 19:00:53 2013 +0200
+++ b/RelaxNG/publidoc.rnc	mer. juin 05 10:15:53 2013 +0200
@@ -588,7 +588,7 @@
 # ~~~~~~ subject
 subject = element subject { subject.content }
 
-subject.content = xsd:NMTOKEN
+subject.content = mixed { sup*, sub* }
 
 # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ abstract ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~