Portion of the MWC 314 spectrum showing permitted Fe ii λ6416.9, λ6432.7, and λ6456.4 emission lines. The spectra are shifted upwards according the orbital phase (the labels show φ and spectrum Nos.). The orbital Doppler shift of the Ne i λ6402.2 absorption line is shown by the vertical curved line (drawn dotted). We show in this paper that the detailed shapes of the emission lines precisely depend on φ, or are mainly caused by orbital modulation. For example, No. 1 (φ = 0.440) and No. 8 (φ = 0.444) reveal almost identical spectra, we observe however 16 m apart, or separated by ~ 8 × P.