Normalised spectrum of epochs E7 (green) and E11 (blue). They are representatives of the blue-shifted and red-shifted absorption features detected during the outburst. The identified transitions in this wavelength range are marked with black dashed lines (in the laboratory rest frame), while the velocities of ±900 km s⁻¹ and ±1150 km s⁻¹ (referred to the rest wavelength of each line after accounting for the systemic velocity) are marked with red and blue dashed lines, respectively. Telluric bands and interstellar features are shown as grey and yellow shadowed regions, respectively.