Notes. ²The redshift and the observed z′ magnitude are taken from the original discovery papers, predominantly Bañados et al. (2016) unless marked as follows: ^a = Willott et al. (2007a), ^b = Venemans et al. (2013), ^c = Jiang et al. (2016), ^d = Mazzucchelli et al. (2017b), ^e = Zeimann et al. (2011), ^f = Matsuoka et al. (2016), ^g = Kim et al. (2015), ^h = Reed et al. (2015), ⁱ = Venemans et al. (2015), ^j = Jiang et al. (2009), ^k = Willott et al. (2007b), ^l = Carnall et al. (2015), ^m = Willott et al. (2010). Column 4 is the date at the start of the observing night, and Col. 5 indicates the nth observing night of that target (first number) and which observation blocks (OBs) were used in the analysis (numbers after the underscore): more than one number indicates stacking of multiple OBs. Column 6 provides the 3σ limiting z′ magnitude of the (stacked) observation, not corrected for galactic foreground extinction (which is given in Col. 7, based on Schlafly & Finkbeiner 2011). The letter attached to the z′ limiting magnitude denotes the catalogue used for photometric calibration of the optical channels g′r′i′z′: S=SDSS (DR12), P=PanSTARRS1, SM=SkyMapper (DR1.1).