Excel Formula: Compare lists, return result if not found

Hello,

I think this is pretty simple, i'm just not quite sure where to start. Whether I need an INDEX formula or its something relatively basic... I realize this can be achieved with a massive IF statement, but obviously, I'd rather just get a proper solution here.

I have a list of raw data, which are "categories" that may or may not contain duplicates. Then, I have a smaller list called "My Categories". I want to compare the raw data to my categories. And if any value in my raw data is not found in "my categories", I want to return a result adjacent to the column. Quite simple, I guess.

Any help is appreciated, and I have attached a sample.

Thanks for your time!

Try

=IF(COUNTIF($B$5:$B$15,D11),"y","n")

Works great, Root_


Thank you very much.