Top panel: example fit for one of our stars; J05019+011 (M4.0 V). Data are shown as black line with uncertainties. The best fit solution is shown as red line, the best solution with ⟨B⟩=0 G as blue dashed line. The absorbing species are indicated together with the effective Landé-g factor for atomic lines. Bottom panel: cornerplot for posterior MCMC parameter distribution. In this example, six field components f₁–f₆ were used, and twelve lines were fit for which one scaling parameter (mag₁–mag₁₁) per line is shown. Corresponding lines are shown in the upper panel in the same order. The posterior distribution for ⟨B⟩=ΣB_if_i is included in the plot at the bottom row. Inset panel: relative distribution of filling factors f_i for field components B_i. Uncertainties of individual field components are indicated as cyan lines.