Relationship between the extinction-normalized 862 nm DIB and the Schlafly et al. (2016) total to selective extinction R′_V for APOGEE LOSs (dots). For low to moderate extinctions, despite the large scatter, ${\mathrm{D}\mathrm{I}\mathrm{B}}_{\text{norm }}^{862}$ decreases with $R_V^{\mathrm{\prime }-1}$. To illustrate the trend, iso-contours of data point numbers per 0.007 × 0.04 rectangular bins in $R_V^{\mathrm{\prime }-1}$ × ${\mathrm{D}\mathrm{I}\mathrm{B}}_{\text{norm }}^{862}$ are drawn for 40, 80, and 120 points. The trend is reversed at very high extinctions, as shown by the superimposed results of Ramírez-Tannus et al. (2018) for M17 (thick crosses). For these data points we neglected the difference between R′_V and R_V. All markers are colour-coded according to the LOS extinction.