Extinction-normalized 862 nm DIB EW for selected data from the second catalogue (Gaia Collaboration 2023a) as a function of the sky-interpolated Planck spectral index β (see text for selection). The colour scale refers to the distance to the Plane of the spatial bin, and excludes distances below 200 pc. Extinction values are restricted to the 1.5 to 2.5 mag interval. An orthogonal distance regression linear fit is superimposed (see text).