Index: /trunk/data/maps.xsd
===================================================================
--- /trunk/data/maps.xsd	(revision 9516)
+++ /trunk/data/maps.xsd	(revision 9517)
@@ -38,5 +38,5 @@
 	<xs:simpleType name="zoom">
 		<xs:restriction base="xs:integer">
-			<xs:minInclusive value="1" />
+			<xs:minInclusive value="0" />
 			<xs:maxInclusive value="24" />
 		</xs:restriction>