Index: trunk/data/validator/combinations.mapcss
===================================================================
--- trunk/data/validator/combinations.mapcss	(revision 8746)
+++ trunk/data/validator/combinations.mapcss	(revision 8754)
@@ -325,2 +325,8 @@
   throwWarning: tr("{0} together with {1}", "{0.key}", "{1.key}");
 }
+
+/* see #11837 */
+way[layer][layer<0][bridge][bridge!=no][location!=underground][indoor!=yes][!tunnel],
+way[layer][layer>0][tunnel][tunnel!=no][location!=overground][indoor!=yes][!bridge] {
+  throwWarning: tr("Suspicious tag/value combination: {0} and {1}", "{2.tag}", "{0.tag}");
+}