XLS

File Format
Name	XLS
Ontology	Electronic File Formats Document XLS
Extension(s)	.xls
MIME Type(s)	application/vnd.ms-excel

Microsoft Office EXCEL 97-2007

The Excel Binary File Format (.xls) Structure is the binary file format used by Microsoft Excel 97, 2000, 2002, and Office Excel 2003. It is also supported by Microsoft Office Excel 2007.

Later Excel versions use XLSX as their native format, though they still support the older format as well.

References

• Binary file format specification *.xls (97-2007) format
• Why are the Microsoft Office file formats so complicated? (And some workarounds)
• Typo in Excel spreadsheet apparently led to erroneous result in economic paper that was influential on government policy