I agree, for data validation to work with your defined formula, you have
to uncheck Ignore blanks. However, it's not a general requirement for
data validation to work, when defined names are used.

Brett wrote:
> Try this:
> Open a new workbook. With the active cell at A1, create the defined name
> Valid_Data =isnumber(A1). Then create Data Validation for A1 as Settings /
> Validation criteria / Allow: Custom ; Formula: =Valid_Data.
>
> Now enter a number in A1 - Result: no error - correct.
> Now enter a letter in A1 - Result: no error - incorrect
>
> Now go back to the Data Validation dialog box and uncheck 'Ignore blanks'.
>
> Now enter a number in A1 - Result: no error - correct.
> Now enter a letter in A1 - Result: error - correct
>
>
> "Debra Dalgleish" wrote:
>
>
>>Data Validation lists will work, even if 'Ignore blanks' is checked.
>>
>>Brett wrote:
>>
>>>OK, I figured it out for myself. All I needed to do was uncheck the "Ignore
>>>blanks" check box. For some reason, validation criteria formulas with defined
>>>names won't work unless this is uncheked. Go figure?
>>
>>
>>--
>>Debra Dalgleish
>>Excel FAQ, Tips & Book List
>>http://www.contextures.com/tiptech.html
>>
>>
>


--
Debra Dalgleish
Excel FAQ, Tips & Book List
http://www.contextures.com/tiptech.html