Index: trunk/data/validator/geometry.mapcss
===================================================================
--- trunk/data/validator/geometry.mapcss	(revision 13074)
+++ trunk/data/validator/geometry.mapcss	(revision 13083)
@@ -46,4 +46,9 @@
   assertMatch: "node bridge=yes";
   assertMatch: "node bridge=viaduct";
+}
+
+/* {0} on a node, should be a way or relation */
+node[boundary=administrative] {
+  throwWarning: tr("{0} on a node. Should be used on a way or relation.", "{0.tag}");
 }