Cumulative Stokes V profiles of V410 Tau computed from the observed (histogram) and theoretical (thick solid line) LSD circular polarisation spectra of V410 Tau shown in Fig. 5. The CSV profiles are shifted vertically according to their rotational phases similar to the Stokes V profiles in Fig. 5. The first three panels show the CSV spectra computed with a) forward integration, b) backward integration, and c) weighted mean of the backward and forward integration. The last panel d) shows the result of converting the CSV profiles in panel c) to the 1−ℛ_I normalisation according to Eq. (19).