» Retrieving List Values that Do Not Appear in a Second List
We want to create a new list consisting of the values from List1 (column A) that are not common to List2 (column B) as well.
Use the INDEX, SMALL, IF, COUNTIF, and ROW functions as shown in the following Array formula:
Enter the formula in cell C2 and copy it down the column until the #REF! error is returned.