A(C) vs. [Fe/H] for J1907 (filled red circle) vs. different literature samples from Yoon et al. (2016, gray triangles), Hansen et al. (2019, black X), Bonifacio et al. (2018, open black circles), and star SDSS J100714+160154 from Frebel et al. (2014, filled black circle). Horizontal lines describe the high- and low-carbon band according to Spite et al. (2013, dashed) or Yoon et al. (2016, dotted). Diagonal lines are [C/Fe] = 0 (dashed) and +1.0 (continuous). All comparison samples, except for SDSS J100714+160154, belong to the MW.