Index: trunk/data/defaultpresets.xml
===================================================================
--- trunk/data/defaultpresets.xml	(revision 8427)
+++ trunk/data/defaultpresets.xml	(revision 8428)
@@ -5088,4 +5088,11 @@
             <combo key="leisure" text="Type" values="stadium,pitch,sports_centre" />
         </item> <!-- Beach Volleyball -->
+            <item name="Billiards" icon="styles/standard/sport/billiards.svg" type="node,closedway" preset_name_label="true">
+            <link href="http://wiki.openstreetmap.org/wiki/Tag:sport=billiards" />
+            <space />
+            <key key="sport" value="billiards" />
+            <reference ref="name_operator" />
+            <combo key="leisure" text="Type" values="stadium,pitch,sports_centre" />
+        </item> <!-- Billiards -->
         <item name="Golf" icon="styles/standard/sport/golf.svg" type="node,closedway" preset_name_label="true">
             <link href="http://wiki.openstreetmap.org/wiki/Tag:sport=golf"
Index: trunk/data/validator/deprecated.mapcss
===================================================================
--- trunk/data/validator/deprecated.mapcss	(revision 8427)
+++ trunk/data/validator/deprecated.mapcss	(revision 8428)
@@ -477,2 +477,11 @@
   suggestAlternative: "sport=ice_hockey";
 }
+
+/* see #11471 */
+*[sport=billard],
+*[sport=billards],
+*[sport=billiard] {
+  throwWarning: tr("{0} is deprecated", "{0.tag}");
+  suggestAlternative: "sport=billiards";
+  fixAdd: "sport=billiards";
+}