Band positions of the unidentified emission features as function of distance to the central object for V854 Cen (black squares) and the Red Rectangle (red circles). There is no measurement of the λ6617 feature at 6″. Error bars reflect 1σ errors. All RR bands are blueshifted with respect to the corresponding bands in V854 Cen. The λ8692 band is only covered in V854 Cen and is detected on both sides of the star.