For a CFB of major version 4, the rest of the first sector, 3,584 bytes of zeroes.480 bytes for remainder of the 512-byte header, which fills the first sector for a CFB of major version 3.2-byte Hex value 0900 (indicating the sector size of 512 bytes used for major version 3) or 0C00 (indicating the sector size of 4096 bytes used for major version 4).This byte order applies to all CFB files. 2-byte Hex value FEFF indicating little-endian byte order for all integer values.2-byte Hex value 0300 indicating CFB major version 3 or value 0400 indicating CFB major version 4.2-byte Hex value 3E00 indicating CFB minor version 3E.Gary Kessler notes that the beginning of this string looks like "DOCFILE" Header Signature for the CFB format with 8-byte Hex value D0CF11E0A1B11AE1.An XLS file in BIFF8 (or BIFF5) encoding begins as follows, with all values given as they occur in the physical file, for example when viewed using a Hex dump utility: Hence the mandatory Workbook Globals Substream can be used to recognize the BIFF version. A substream has a BoF (beginning of file) record that includes an indicator for the BIFF version. These streams and substreams employ BIFF8 encoding for component binary records.
FILES CREATED IN MICROSOFT OFFICE EXCEL 2013 ARE CALLED SERIES
Each binary stream or substream is written as a series of binary records.Īn XLS file must contain a single Workbook stream which has a single Globals Substream with at least one sheet substream, which could be a Worksheet Substream, Chart Sheet Substream, Macro Sheet Substream, or Dialog Sheet Substream. It consists of storages, streams, and substreams. Ī CFB provides a file-system-like structure within a file for the storage of arbitrary, application-specific streams of data. The structure of an XLS file since 1993 (BIFF5/Excel 5.0) is an OLE (object linking and embedding) compound file as specified in. Since 2008, the structure for the XLS format used since Excel 97 has been kept up-to-date at. The specification released in 2007 is available as Microsoft Office Excel 97-2007 Binary File Format Specification. See Notes below for more detail on versions of BIFF.Īlthough the XLS format is proprietary, since 2007 it has been covered by Microsoft's Open Specification Promise. As of late 2019, the documentation for File formats that are supported in Excel, from Microsoft, lists two variants of XLS format, distinguishing between "Excel 5.0/95 Binary file format" and "Excel 97-Excel 2003 Binary file format." These correspond to BIFF5 and BIFF8, respectively. Although it cannot support the latest functionality of the Excel application, BIFF8 has continued to be available as an alternative to the XLSX/OOXML format, standardized as ISO/IEC 29500, for saving spreadsheet files in Excel. This format description is primarily for version 8 of BIFF (BIFF8), introduced with Excel 97 in 1997. The format is also referred to as Binary Interchange File Format (BIFF) in Microsoft's technical documentation. xls extension and referred to as XLS or MS-XLS, was the default format used for spreadsheets in Excel through Microsoft Office 2003. The Microsoft Excel Binary File format, with the. Microsoft Office Excel 97-2003 Binary File Format (.xls).