Position of BDF521 and BDF2195 on the CIII](EW) vs. Lyα(EW) plane (left panel), and on the CIII](EW) vs. M_UV plane (right panel), compared to z ≳ 6 objects from the literature: Stark et al. (2015a), Watson et al. (2015), Stark et al. (2017), Laporte et al. (2017), Schmidt et al. (2017), Hutchison et al. (2019), Jiang et al. (2021), and Topping et al. (2021). In the left panel we also show objects at z ∼ 1.5–3 from Stark et al. (2014), the CIII] emitters at z = 3.5–4.5 from the VANDELS survey (Marchi et al. 2019), the Lyman-continuum leaker Ion2 (z = 3.2, Vanzella et al. 2020), and the ultra-faint star-forming clumps at z ∼ 3 from Vanzella et al. (2017a,b). All upper limits are at 3σ. See the legend for symbols and colours.