940 Microsoft Excel for Windows 2007 onwards Spreadsheet From Microsoft Office 2007 onwards, the core output format of MS Excel has been based on the Office Open XML (OOXML) file format. The ISO standard for OOXML is ISO/IEC DIS 29500. An OOXML file format consists of a compressed zip archive that is designated according to which file type it is. Further detail on OOXML can be found within fmt/189 - Microsoft Office Open XML. Text 1 Digital Preservation Department / The National Archives 28 Oct 2009 This format can be identified via a container signature in DROID version 6 or later. The PRONOM database cannot currently represent container signatures. 19 Apr 2012 application/vnd.openxmlformats-officedocument.spreadsheetml.sheet MIME fmt/214 PUID xlsx File extension Has lower priority than 2679 XLSX Strict OOXML Spreadsheet Is supertype of 1387 Microsoft Excel Non-XML Binary Workbook Is supertype of 1390 Microsoft Excel Template Is supertype of 1426 Microsoft Excel Macro-Enabled Template Is supertype of 1427 Microsoft Excel Macro-Enabled Add-In