Velocity shifts of several DIBs toward HD 62542 (red; UVES spectra), relative to those toward 20 Aql (black; HARPS spectra), scaled to similar central depths. (Note the different y-axis scales for HD 62542 (right) and 20 Aql (left).) On the top line of each panel, the 20 Aql profile is shifted to 14 km s⁻¹ (the velocity of the main, predominantly molecular component toward HD 62542); on the bottom line of each panel, the 20 Aql profile is shifted to 27 km s⁻¹ (the velocity of the generally strongest of the predominantly atomic “other” components); in the middle is a composite constructed from the 20 Aql profile, with equal contributions at 14 and 27 km s⁻¹ (except in the leftmost panel, which compares the aligned K I λ4044 profiles). Toward HD 62542, the λ4963.9 C₂–DIB (which can be present in diffuse molecular gas) appears to be concentrated almost exclusively in the main component, the λ5797.2 DIB appears to have some contribution from the higher velocity component, and the λ6196.0 and λ5780.6 DIBs (which trace primarily atomic gas) appear to have roughly equal contributions from the two components.