Use Excel data ... validation rule that recognizes a duplicate value, so you’ll need to combine the feature with Excel’s COUNTIF() function. In this article, I’ll show you how to do this in ...

Open the Data Validation table by following the steps provided in the above fix. Under the Settings tab, click on the Clear All button. Click OK to save the changes. Now, open the Data Validation ...

Excel's data validation ... Excel’s Table object isn’t supported in the menu version, so #3 won’t work in .xls files. The browser version supports existing validation controls, but you ...