5.6 http://schemas.microsoft.com/office/spreadsheetml/2011/1/ac Schema

 <xsd:schema targetNamespace="http://schemas.microsoft.com/office/spreadsheetml/2011/1/ac" elementFormDefault="qualified" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:x="http://schemas.openxmlformats.org/spreadsheetml/2006/main" xmlns="xl12AcSchemaUri">
   <xsd:import namespace="http://schemas.openxmlformats.org/officeDocument/2006/relationships" schemaLocation="orel.xsd"/>
   <xsd:import namespace="http://schemas.openxmlformats.org/spreadsheetml/2006/main" schemaLocation="xlbasictypes.xsd"/>
   <xsd:element name="list" type="x:ST_Xstring"/>
 </xsd:schema>