The orientation of the adsorbed CO molecule affects not only the stretching ν value but also its simulated IR intensity, which is directly proportional to the molecular dipole moment change perpendicular to the surface associated to the vibrational motion, known as surface dipole selection rule. This makes IR-visible perpendicular motions -or with a perpendicular component-while parallel cases get their dipole moment cancelled by a mirror counterdipole generated on the underlying TM surface electronic density. This is exemplified in Fig. for late, middle, and early TM surfaces with decreasing perpendicularity of the adsorbed CO molecule. The simulated IR can be found in Fig. of Section S5 of the SM.