--- a/RelaxNG/publiquiz.rnc	mer. mai 18 13:08:14 2016 +0200
+++ b/RelaxNG/publiquiz.rnc	jeu. mai 26 11:39:29 2016 +0200
@@ -66,7 +66,7 @@
 
 quiz.content =
    component.head?,
-   instructions,
+   instructions?,
    (engine | composite),
    help?,
    answer?