TESS Cycle 1 CPD depicting our identification of P_rot measurements that are the result of systematic errors. Measurements of P_rot < 15 days with periodograms powers greater than the 30th percentile power for this cycle are plotted as blue circles. P_rot measurements ranging from 3.0 to 3.5 days with periodogram powers <0.1 are marked with orange crosses and are likely the result of an (unspecified) systematic error in the Cycle 1 data. Setting a P_rot range and raising the minimum power required for consideration allows us to remove a number of unreliable measurements missed with the cut illustrated in Figure 4.