Question

How to mark a cell value as mandatory in excel. I have a sheet which contains 3 headers and I would like to mark the column values of header3 as mandatory from a possible set of values (i.e. even if the user doesn’t select a value a default value should be set for the cell)

Answer 1

Use Validation on Cells where you want to perform these constraints.

Like : Select Range of Cells where you want to put this constraint.

Now open Data Validation Dialog and Select List from Allow drop down in Setting Tab. Provide your source (possible values) in comma separate values