Index: trunk/data/validator/deprecated.mapcss
===================================================================
--- trunk/data/validator/deprecated.mapcss	(revision 9745)
+++ trunk/data/validator/deprecated.mapcss	(revision 9747)
@@ -787,2 +787,7 @@
   fixChangeKey: "amenity => leisure";
 }
+
+/* #12494 */
+*[/.+_[0-9]$/][!/^note_[0-9]$/][!/^description[0-9]$/] {
+  throwWarning: tr("questionable key (ending with a number): {0}", "{0.key}");
+}