WISE1/WISE2 median magnitude versus MAD diagrams. From left to right: initial sample with previous identified outliers; the same diagram with previous outliers removed and new outliers based on variability identified with dark yellow open diamonds; the final cleaned dataset with all outliers removed, where the insert panels show the range of 7.5 < median_WISE1/WISE2< 11.0 mag and MAD_WISE1/WISE2<0.02 mag. Error bars show the short-term (approximately five to ten days) variability within each epoch calculated by MAD (same below). See text for details.