A primary goal of cryo-SEVI is to use cryogenic cooling to bring the anions into their ground vibrational state, thereby eliminating vibrational hot bands in the photoelectron spectrum, and to rotationally cool the anions as much as possible to obtain narrow rotational profiles. However, the extent to which one can extract vibrational frequencies from these spectra and, more generally, learn about the neutral potential energy surface accessed by photodetachment is limited by the selection rules that govern photoelectron spectroscopy.