The Microsoft Excel File Format - OpenOffice.org

5.8 BOF – Beginning of File
5.8 BOF – Beginning of File
BIFF2 BIFF3 BIFF4 BIFF5 BIFF8
0009 H 0209 H 0409 H 0809 H 0809 H
The BOF record is the first record of any kind of stream or substream:
• The Worksheet Stream (➜4.1.1) and the Chart Stream (➜7.1.1)
• All substreams in the Workbook Stream (the Sheet Substream and the Workbook Globals Substream, ➜4.1.2, and the
Chart Substream, ➜7.1.2)
• The Workspace Stream.
A BOF record will never be encrypted, regardless of its type and position in the stream.
If a BIFF8 version of Excel (Excel 8.0 and newer) writes a BIFF5 workbook, it writes a wrong BIFF version in BOF
! records of the Sheet Substreams. Only the leading BOF record of the Workbook Globals Substream contains the
correct value and should be used to determine the BIFF version for the entire stream.
5.8.1 BOF Records Written by Excel
Record BOF, BIFF2 (record identifier is 0009 H ):
Offset Size Contents
0 2 BIFF version (not used)
2 2 Type of the following data: 0010 H = Sheet
0020 H = Chart
0040 H = Macro sheet
Record BOF, BIFF3 (record identifier is 0209 H ) and BIFF4 (record identifier is 0409 H ):
Offset Size Contents
0 2 BIFF version (not used)
2 2 Type of the following data: 0010 H = Sheet
0020 H = Chart
0040 H = Macro sheet
0100 H = Workspace (BIFF3W/BIFF4W only)
4 2 Not used
Record BOF, BIFF5 (record identifier is 0809 H ):
Offset Size Contents
0 2 BIFF version (always 0500 H for BIFF5). Should only be used, if this record is the leading
workbook globals BOF (see above).
2 2 Type of the following data: 0005 H = Workbook globals
0006 H = Visual Basic module
0010 H = Sheet or dialogue (see SHEETPR, ➜5.97)
0020 H = Chart
0040 H = Macro sheet
0100 H = Workspace (BIFF5W only)
4 2 Build identifier, must not be 0
6 2 Build year
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