I am trying to use data validation in excel to allow a user to only input a number within a specific cell, otherwise, they can also type "unknown" within the same cell. Right now I'm using ISNUMBER function, however, I don't know how to include "unknown" too. I do not want this to be a dropdown list.
1 Answer
You can use a custom formula like this:
=OR(ISNUMBER(A1),A1="unknown")See screenshot for the data validation in action.
