How do you restrict a cell to accepting only "Y" or "N" ?

[NickR2]

We need to format a cell so that it will only accept a "Y" for yes, or a "N"
for no.
How can this be done?

Thank you

 

[Stephen]

Select the cell (say,A1):
Data > Validation
Allow:
select Custom
Formula:
=(OR(A1="Y",A1="N"))

 

[BoniM]

Select the cell or range of cells and choose Validation from the Data menu.
Change Allow to List and in the source box, type: Y, N
This will allow the entry of a captial y or a captial n only in this cell or
range.
You can also click the input message tab and add a message that will appear
when a user enters the cell, telling them the restrictions or enter an error
message that the user receives when they enter incorrect data.