I have a set of assumptions, in which I need one column to serve as a unique ID, per assumption. My list is much longer than attached, but for purposes of illustrating the issue, have condensed it. What I need is a formula that will basically look at all BUT the line in question, to see if that value in the line is in any of those other lines. I think what I need is essentially a disjointed (non-contiguous) set of cells, to serve as the area in which to look. Any ideas for how to get this 'straddling' sort of array, so that I can easily copy it up/down, and get the correct portions to cover? I've done it one way, but wondering if there's anything more concise (not having to use two functions, within the formula?