The Row & Column Pairs forms assist in identifying x-wing patterns. In the example below, the Column Pairs form highlights an 4 cell x-wing pattern, see rectangle. 3 can only occur in the corner cells of the x-wing rectangle. The 3's in cells E1, E3, E6, I1, I3 & I6 can all be removed.
After clearing the target digit, the 3 numeric button needs to be clicked again to refresh the Column Pairs for further inspection.