--- a/RelaxNG/publidoc.rnc	ven. oct. 28 10:41:08 2011 +0200
+++ b/RelaxNG/publidoc.rnc	jeu. nov. 10 13:04:58 2011 +0100
@@ -206,7 +206,7 @@
 # ~~~~~~ keyword
 keyword = element keyword { keyword.content }
 
-keyword.content = text
+keyword.content = mixed { sup*, sub* }
 
 # ~~~~~~ subjectset
 subjectset = element subjectset { subjectset.content }

--- a/RelaxNG/publidoc.rng	ven. oct. 28 10:41:08 2011 +0200
+++ b/RelaxNG/publidoc.rng	jeu. nov. 10 13:04:58 2011 +0100
@@ -449,7 +449,14 @@
     </element>
   </define>
   <define name="keyword.content">
-    <text/>
+    <mixed>
+      <zeroOrMore>
+        <ref name="sup"/>
+      </zeroOrMore>
+      <zeroOrMore>
+        <ref name="sub"/>
+      </zeroOrMore>
+    </mixed>
   </define>
   <!-- ~~~~~~ subjectset -->
   <define name="subjectset">