"Well-constrained" distance estimate criteria. Each BGPS V2.1 catalog object at ℓ ⩽ 70° is shown, plotted by its integrated posterior DPDF on the d_ML side of the tangent point (P_ML) and the full-width error bar containing ⩾68.3% of the integrated posterior DPDF around d_ML (FW₆₈). The vertical dot–dashed line at P_ML = 0.78 is shown to guide the eye, while the horizontal dashed line marks the FW₆₈ ⩽ 2.3 kpc boundary for a "well-constrained" distance estimate. The gray star identifies the median values of P_ML and FW₆₈ for the well-constrained sample.