Left panel: [C/Fe] vs. luminosity for our sample stars. The dashed–dotted line indicates the dividing line between carbon-enhanced and carbon-normal stars as defined in Aoki et al. (2007). The dashed line corresponds to [C/Fe] = 1.0. Right panel: [C/Fe] vs. [N/Fe]. The two criteria for NEMP stars suggested by Pols et al. (2012) are respectively shown in dotted ([N/Fe] ≥ 1.0 and [N/C] ≥ 0.5) and dashed–dotted lines ([(C+N)/Fe] > 0.9). The filled red stars refer to our sample stars. Non-carbon-enhanced objects studied by previous works (Gratton et al. 2000; Cayrel et al. 2004; Honda et al. 2004; Aoki et al. 2005) are shown by triangles. Metal-poor stars from Spite et al. (2005; filled diamonds), and CEMP stars from Aoki et al. (2007; crosses) are also plotted for comparison. The candidate CNEMP object J2114-0616 is marked.