Zinc abundance as a function of metallicity. The measurement for BS 16920-017 is from Honda et al. (2011), that of BD+44° 493 is from Roederer et al. (2016). the open circles are giants (Cayrel et al. 2004), filled circles are dwarfs (Bonifacio et al. 2009), downward arrows are upper limits for dwarfs (Bonifacio et al. 2009). The two red open circles are CEMP-no stars. The red full circle with a question mark is the Zn abundance derived in the case of log g = 4.5 for SDSS J0929+0238.