Index: trunk/data/maps.xsd
===================================================================
--- trunk/data/maps.xsd	(revision 8344)
+++ trunk/data/maps.xsd	(revision 8349)
@@ -671,4 +671,5 @@
 								</xs:complexType>
 							</xs:element>
+							<!-- list of HTTP headers, that indicate "no tile at this zoom level" situation -->
 							<xs:element name="no-tile-header" minOccurs="0" maxOccurs="unbounded">
 								<xs:complexType>
@@ -677,4 +678,6 @@
 								</xs:complexType>
 							</xs:element>
+							<!-- tile size provided by imagery source. Default - 256 -->
+							<xs:element name="tile-size" minOccurs="0" maxOccurs="1" type="xs:positiveInteger" />
 						</xs:choice>
 					</xs:sequence>