Polarized S/N: for each polarization-sensitive observation in our catalog, we plot the de-biased polarized flux density S/N against the intensity flux density. Observing bands are indicated in the labels. For cases where de-biasing renders a S/N less than 0.1, we plot a data point at 0.1. The vertical grey bands indicate the lowest and narrowest flux density bin that has a median S/N of 1.0 and at least 20 entries. The center of the bin is spelled out in the label.