Index: /trunk/src/org/openstreetmap/josm/data/Preferences.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/data/Preferences.java	(revision 11423)
+++ /trunk/src/org/openstreetmap/josm/data/Preferences.java	(revision 11424)
@@ -68,4 +68,6 @@
 import org.openstreetmap.josm.data.preferences.Setting;
 import org.openstreetmap.josm.data.preferences.StringSetting;
+import org.openstreetmap.josm.gui.preferences.validator.ValidatorTagCheckerRulesPreference;
+import org.openstreetmap.josm.gui.preferences.validator.ValidatorTagCheckerRulesPreference.RulePrefHelper;
 import org.openstreetmap.josm.io.OfflineAccessException;
 import org.openstreetmap.josm.io.OnlineResource;
@@ -1521,4 +1523,10 @@
             migrateOldColorKeys();
         }
+        // drop in September 2017
+        if (loadedVersion < 11424) {
+            addNewerDefaultEntry(
+                    "validator.org.openstreetmap.josm.data.validation.tests.MapCSSTagChecker.entries",
+                    "resource://data/validator/territories.mapcss");
+        }
 
         for (String key : OBSOLETE_PREF_KEYS) {
@@ -1570,4 +1578,16 @@
     }
 
+    private void addNewerDefaultEntry(String key, final String url) {
+        Setting<?> setting = settingsMap.get(key);
+        if (setting instanceof MapListSetting) {
+            List<Map<String, String>> l = new ArrayList<>(((MapListSetting) setting).getValue());
+            if (l.stream().noneMatch(x -> x.values().contains(url))) {
+                RulePrefHelper helper = ValidatorTagCheckerRulesPreference.RulePrefHelper.INSTANCE;
+                l.add(helper.serialize(helper.getDefault().stream().filter(x -> url.equals(x.url)).findFirst().get()));
+                putListOfStructs(key, l);
+            }
+        }
+    }
+
     /**
      * Enables or not the preferences file auto-save mechanism (save each time a setting is changed).