Strange. It would only stop them from entering the text once they navigate
away from the cell, and only if 'Show error alert after invalid data is
entered' is checked in the Error Alert tab of the Data Validation menu form.

Biff's solution should work too.

"Lakeville" wrote:

I thought it was case sensitive, but it is not working that way for me.

"Basil" wrote:
You could just select the 'List' option and type Y,N in the criteria. It is
case sensitive.

"Lakeville" wrote:

I want to ensure that the data in a cell is either a capitalized Y or a
capitalized N. I understand how to do the data validation of a list with Y &
N. And I understand how to enforce capitalization: =EXACT(A1,UPPER(A1)).
However, I don't understand how to enforce both for the same cell.