Microsoft Office Open XML (MSOOXML) Formula definitions are maybe wrong. This essay debunk the myth that MSOOXML is superior to the Open Document Format (ODF) because it include a 324 page "Formula Definition".
http://www.robweir.com/blog/2007/07/formula-for-failure.html
Some of those errors are quite stupid other are probably less of a problem, following is a demonstration on one function (ceiling)
http://www.openmalaysiablog.com/2007/07/mathematically-.html
Rob says: here [1] MS repeats again the same affirmation: "Ecma 376 contains full documentation for spreadsheet formulas"
Yes, i know: Full documentation for Microsoft and ECMA = copy and paste of Excel formula Online Help
[1] http://www.odfalliance.in/files/Comments%20on%20Additional%20Points%20receiv... Page 4, item 9b)
retrieved from http://www.odfalliance.in/OOXML.html