--- a/RelaxNG/publiset.rnc	dim. mai 24 19:12:25 2015 +0200
+++ b/RelaxNG/publiset.rnc	mer. mai 27 22:29:05 2015 +0200
@@ -237,7 +237,7 @@
    remap.attributes
 
 composition.head.content =
-   (title, shorttitle?, subtitle*)?
+   (title & shorttitle? & subtitle*)?
  & identifier*
  & copyright*
  & collection?