Index: trunk/data/validator/combinations.mapcss
===================================================================
--- trunk/data/validator/combinations.mapcss	(revision 14364)
+++ trunk/data/validator/combinations.mapcss	(revision 14593)
@@ -88,4 +88,5 @@
 
 /* {0.key} without {1.tag} */
+node[fire_hydrant:type         ][emergency!=fire_hydrant][disused:emergency!=fire_hydrant],
 *[transformer                  ][!power],
 way[fence_type                 ][barrier!=fence],
@@ -116,4 +117,5 @@
 
 /* {0.tag} without {1.key} (warning level) */
+node[emergency=fire_hydrant][!fire_hydrant:type],
 way[boundary=administrative][!admin_level],
 relation[boundary=administrative][!admin_level],
@@ -526,2 +528,7 @@
   assertMatch: "way highway=primary lanes=3";
 }
+
+/* #15774 */
+node[emergency=fire_hydrant][fire_hydrant:count][fire_hydrant:count!=1] {
+  throwOther: tr("{0} together with {1}. Tag each hydrant separately.", "{0.tag}", "{1.tag}");
+}