Index: trunk/data/validator/geometry.mapcss
===================================================================
--- trunk/data/validator/geometry.mapcss	(revision 6658)
+++ trunk/data/validator/geometry.mapcss	(revision 6680)
@@ -34,2 +34,11 @@
   throwWarning: tr("{0} inside {1}", "amenity=parking", "amenity=parking");
 }
+
+/* see ticket #9556 */
+area:closed:areaStyle[tag("natural") = parent_tag("natural")] ⧉ area:closed:areaStyle[natural] {
+  throwWarning: tr("Overlapping Identical Natural Areas");
+}
+
+area:closed:areaStyle[tag("landuse") = parent_tag("landuse")] ⧉ area:closed:areaStyle[landuse] {
+  throwWarning: tr("Overlapping Identical Landuses");
+}