Select the cell(s) and using data Validation, choose Custom and enter this
formula:
=FIND("P",B2)0
in this case B2 is the first cell in the range selected of a multiple cell
selection.
It will alert if a P is not in the entry, but won't tell you if several Ps
are entered, just if there isn't one.

"aditya" wrote:

data in column B is of 9 or 10 or 11 or 12 digit.
In every case it contains alphabet "P" whereas others are digit.
e.g. 10P060509
125P695847

how can i check this through data validation?