Microsoft tells us that many worksheet functions are ‘deprecated.’ So what does that mean, exactly? Wikipedia tells us that deprecation is a status applied to a computer software feature, characteristic, or practice indicating it should be avoided, typically because of being superseded. Each new generation of Excel seems to deprecate additional worksheet functions. For example, Microsoft’s help topic for the FTEST function tells us:
This function has been replaced with one or more new functions that may provide improved accuracy and whose names better reflect their usage. Although this function is still available for backward compatibility, you should consider using the new functions from now on, because this function may not be available in future versions of Excel. In Excel 2010 and above, as you type a function name, Excel lists the functions that match and provides a short description.