Index: trunk/data/validator/combinations.mapcss
===================================================================
--- trunk/data/validator/combinations.mapcss	(revision 6877)
+++ trunk/data/validator/combinations.mapcss	(revision 6880)
@@ -15,5 +15,4 @@
 *[sidewalk                     ][!highway],
 *[smoothness                   ][!highway],
-*[snowplowing                  ][!highway],
 *[step_count                   ][!highway],
 *[tracktype                    ][!highway],
@@ -113,4 +112,9 @@
 }
 
+/* {0.key} without {1.key}, {2.key} or {3.key} */
+*[snowplowing                  ][!highway][!amenity][!leisure] {
+  throwWarning: tr("{0} without {1}, {2} or {3}", "{0.key}", "{1.key}", "{2.key}", "{3.key}");
+}
+
 /* {0} on suspicious object */
 *[tunnel  ][!highway][!railway][!waterway][public_transport != platform][man_made != pipeline],