Formulas added in Excel 2010 and later

Excel 2010 and later versions added functions which weren't defined in the original file specification. These functions are referred to by Microsoft as "Future Functions". Examples of these functions are ACOT, CHISQ.DIST.RT , CONFIDENCE.NORM, STDEV.P, STDEV.S and WORKDAY.INTL.

Although these formulas are displayed as normal in Excel they are stored with a prefix. For example STDEV.S(B1:B5) is stored in the Excel file as xlfn.STDEV.S(B1:B5). The rust_xlsxwriter crate makes these changes automatically so in general you don't have to worry about this unless you are dealing with features such as Lambda functions, see above. However, if required you can manually prefix any required function with the _xlfn. prefix.

For completeness the following is a list of future functions taken from MS XLSX extensions documentation on future functions.

Note, the Python in Excel functions aren't simple functions and aren't supported.

Future Functions
`_xlfn.ACOT`
`_xlfn.ACOTH`
`_xlfn.AGGREGATE`
`_xlfn.ARABIC`
`_xlfn.BASE`
`_xlfn.BETA.DIST`
`_xlfn.BETA.INV`
`_xlfn.BINOM.DIST`
`_xlfn.BINOM.DIST.RANGE`
`_xlfn.BINOM.INV`
`_xlfn.BITAND`
`_xlfn.BITLSHIFT`
`_xlfn.BITOR`
`_xlfn.BITRSHIFT`
`_xlfn.BITXOR`
`_xlfn.CEILING.MATH`
`_xlfn.CEILING.PRECISE`
`_xlfn.CHISQ.DIST`
`_xlfn.CHISQ.DIST.RT`
`_xlfn.CHISQ.INV`
`_xlfn.CHISQ.INV.RT`
`_xlfn.CHISQ.TEST`
`_xlfn.COMBINA`
`_xlfn.CONCAT`
`_xlfn.CONFIDENCE.NORM`
`_xlfn.CONFIDENCE.T`
`_xlfn.COT`
`_xlfn.COTH`
`_xlfn.COVARIANCE.P`
`_xlfn.COVARIANCE.S`
`_xlfn.CSC`
`_xlfn.CSCH`
`_xlfn.DAYS`
`_xlfn.DECIMAL`
`ECMA.CEILING`
`_xlfn.ERF.PRECISE`
`_xlfn.ERFC.PRECISE`
`_xlfn.EXPON.DIST`
`_xlfn.F.DIST`
`_xlfn.F.DIST.RT`
`_xlfn.F.INV`
`_xlfn.F.INV.RT`
`_xlfn.F.TEST`
`_xlfn.FILTERXML`
`_xlfn.FLOOR.MATH`
`_xlfn.FLOOR.PRECISE`
`_xlfn.FORECAST.ETS`
`_xlfn.FORECAST.ETS.CONFINT`
`_xlfn.FORECAST.ETS.SEASONALITY`
`_xlfn.FORECAST.ETS.STAT`
`_xlfn.FORECAST.LINEAR`
`_xlfn.FORMULATEXT`
`_xlfn.GAMMA`
`_xlfn.GAMMA.DIST`
`_xlfn.GAMMA.INV`
`_xlfn.GAMMALN.PRECISE`
`_xlfn.GAUSS`
`_xlfn.HYPGEOM.DIST`
`_xlfn.IFNA`
`_xlfn.IFS`
`_xlfn.IMCOSH`
`_xlfn.IMCOT`
`_xlfn.IMCSC`
`_xlfn.IMCSCH`
`_xlfn.IMSEC`
`_xlfn.IMSECH`
`_xlfn.IMSINH`
`_xlfn.IMTAN`
`_xlfn.ISFORMULA`
`ISO.CEILING`
`_xlfn.ISOWEEKNUM`
`_xlfn.LOGNORM.DIST`
`_xlfn.LOGNORM.INV`
`_xlfn.MAXIFS`
`_xlfn.MINIFS`
`_xlfn.MODE.MULT`
`_xlfn.MODE.SNGL`
`_xlfn.MUNIT`
`_xlfn.NEGBINOM.DIST`
`NETWORKDAYS.INTL`
`_xlfn.NORM.DIST`
`_xlfn.NORM.INV`
`_xlfn.NORM.S.DIST`
`_xlfn.NORM.S.INV`
`_xlfn.NUMBERVALUE`
`_xlfn.PDURATION`
`_xlfn.PERCENTILE.EXC`
`_xlfn.PERCENTILE.INC`
`_xlfn.PERCENTRANK.EXC`
`_xlfn.PERCENTRANK.INC`
`_xlfn.PERMUTATIONA`
`_xlfn.PHI`
`_xlfn.POISSON.DIST`
`_xlfn.QUARTILE.EXC`
`_xlfn.QUARTILE.INC`
`_xlfn.QUERYSTRING`
`_xlfn.RANK.AVG`
`_xlfn.RANK.EQ`
`_xlfn.RRI`
`_xlfn.SEC`
`_xlfn.SECH`
`_xlfn.SHEET`
`_xlfn.SHEETS`
`_xlfn.SKEW.P`
`_xlfn.STDEV.P`
`_xlfn.STDEV.S`
`_xlfn.SWITCH`
`_xlfn.T.DIST`
`_xlfn.T.DIST.2T`
`_xlfn.T.DIST.RT`
`_xlfn.T.INV`
`_xlfn.T.INV.2T`
`_xlfn.T.TEST`
`_xlfn.TEXTJOIN`
`_xlfn.UNICHAR`
`_xlfn.UNICODE`
`_xlfn.VAR.P`
`_xlfn.VAR.S`
`_xlfn.WEBSERVICE`
`_xlfn.WEIBULL.DIST`
`WORKDAY.INTL`
`_xlfn.XOR`
`_xlfn.Z.TEST`

The dynamic array functions shown in the Dynamic Array support section are also future functions, however the rust_xlsxwriter library automatically adds the required prefixes on the fly so you don't have to add them explicitly.

Dynamic Array Functions
`_xlfn.ANCHORARRAY`
`_xlfn.LAMBDA`
`_xlfn.RANDARRAY`
`_xlfn.SEQUENCE`
`_xlfn.SINGLE`
`_xlfn.SORTBY`
`_xlfn.UNIQUE`
`_xlfn.XLOOKUP`
`_xlfn.XMATCH`
`_xlfn._xlws.FILTER`
`_xlfn._xlws.SORT`

Working with the rust_xlsxwriter library

Formulas added in Excel 2010 and later