Redshift-space monopole (left side) and quadrupole (right side) of the marked correlation function for the tanh-mark with parameters fixed to (a, b) = (0.6, −0.5) and corrected for shot noise. Upper panels show the multipoles themselves with colours referring to different gravity simulations. Displayed is the mean over five realisations with respective mean standard deviations as the errorbars. For the monopole the horizontal dashed line in black indicates an amplitude of 1 and for the quadrupole an amplitude of 0. Lower panels show the S/N, as in Eq. (37), with according colours for the different MG models. Shaded regions refer to the error of a single measurement divided by the mean error of the difference and dashed lines in the lower panels indicate a S/N of ±3.