--- a/RelaxNG/publidoc.rnc	mar. avril 29 13:50:50 2014 +0200
+++ b/RelaxNG/publidoc.rnc	mar. mai 13 12:59:42 2014 +0200
@@ -584,9 +584,12 @@
 
 image.attributes =
    media.id.attribute
- & image.type?
+ & image.type.attribute?
+ & alt.attribute?
 media.id.attribute = attribute id { xsd:NMTOKEN }
-image.type = attribute type { "cover" | "thumbnail" | "icon" | "animation" }
+image.type.attribute = attribute type {
+   "cover" | "thumbnail" | "icon" | "animation" }
+alt.attribute = attribute alt { text }
 
 media.image.content =
    copyright?,