"At least XLSX is an open and documented format." The documentation diverges from the excel implementation in so many places that there's a special document (w

"At least XLSX is an open and documented format." The documentation diverges from the excel implementation in so many places that there's a special document (which itself is incomplete): http://msdn.microsoft.com/en-us/library/dd922181(v=office.12).aspx http://msdn.microsoft.com/en-us/library/dd922181(v=office.12... "Are the rules for Excel CSV parsing written down anywhere?" They are loosely described in ECMA-376 section 18.8.30 under the "General" format code. But like with most details surrounding XLS and XLSX, the documentation is barely coherent and incorrect in some places.