BIFF2

BIFF2, short for Binary Interchange File Format version 2, is an early binary file format used by Microsoft Excel to store workbooks. It followed the earliest BIFF version and preceded later variants such as BIFF3 and BIFF4. BIFF2 appeared during the late 1980s, alongside the early Excel releases for Windows and the accompanying Macintosh versions. Files written in this format commonly used the .xls extension, reflecting its role as the standard workbook container for that era.

The BIFF2 format is binary and organized as a sequence of records. Each record carries a two-byte identifier that specifies the record type, a two-byte length field, and a data payload of the indicated length. This record-based structure allows BIFF2 to encode a range of workbook components, including sheet definitions, cell values (numbers and text), basic formatting attributes, and sheet relationships. While exact details are not publicly documented in a contemporary open standard, the general approach facilitates storing multi-sheet workbooks with cell data and simple formatting.

BIFF2 is primarily of historical interest today. It was superseded by subsequent BIFF variants as Excel expanded its feature set, improved cross-platform compatibility, and adopted more complex data representations. Because it is older and less well documented, BIFF2 can present particular challenges for data recovery or conversion, making preservation and emulation efforts relevant for archival projects.

See also: BIFF, Microsoft Excel file formats, digital preservation.