Index: trunk/data/validator/deprecated.mapcss
===================================================================
--- trunk/data/validator/deprecated.mapcss	(revision 7078)
+++ trunk/data/validator/deprecated.mapcss	(revision 7105)
@@ -200,2 +200,8 @@
   assertMatch: "node day_on=0-12";
 }
+
+/* see #10000, http://wiki.openstreetmap.org/wiki/Tag%3Aaccess%3Ddesignated */
+*[access=designated] {
+  throwWarning: tr("''{0}'' is meaningless, use more specific tags, e.g. ''{1}''", "access=designated", "bicycle=designated");
+  assertMatch: "way access=designated";
+}