Index: trunk/data/validator/relation.mapcss
===================================================================
--- trunk/data/validator/relation.mapcss	(revision 8523)
+++ trunk/data/validator/relation.mapcss	(revision 11146)
@@ -17,4 +17,5 @@
 relation[type=enforcement][!enforcement] {
   throwWarning: tr("{0} relation without {0} tag", "{1.key}");
+  group: tr("missing tag");
   assertMatch: "relation type=route";
   assertNoMatch: "relation type=route route=train";