Line identifications in the H-band spectra of HD 57372. Upper panel: line identifications in the APOGEE spectrum of HD 57372 at the rotational phase ϕ_rot = 0.375. The hydrogen Brackett series lines are labelled along the top, while metal lines are labelled along the bottom. Unidentified lines are indicated by small red ticks below the spectrum. Lower panel: variability of individual lines as a function of ϕ_rot.