Display N/A in empty cells

Hello,

I wish to display N/A in specific empty cells.
My problem - some of my cells have validation lists and some are connected to formulas.
Can I define it in cell custom format ?
How can I do it ?

Thank you for your help

Hello,

Thank you for your answer.
I need to fill blank input cells with N/A before printing a sheet
in order to avoid blank cells. I thought that there is an option to
use custom formatting in order to display N/A in empty cell without
modifying its value (like marking zero cells with the char -).

I thought to duplicate my sheet and in for every blank cell in the original sheet
place N/A in the second sheet.

Is there any way to solve it by using custom formatting ?

Thank you for your help

Hello,

Thank you for your help.
I will try your suggestion: using if statements and update validation lists.

Thank you for your support