This is kind of a neat trick. Everyone likes “tiger striping” their spreadsheets to make data more visible. What if you could shade your data based on a choice you made from a list? Even better, what if you had multiple, separate rows that you could stripe? Like so:
See how the choice of “Jams,Preserves” at the top right got the two rows corresponding to that choice to highlight!
These directions from Susan Harkins at TechRepublic are a bit involved, but not hard. First, from your list of non-unique entries, extract a list of unique ones. Second, turn that into a drop-down menu. Third, set up conditional validation for a broader range based on that menu choice.