Rotational properties of our working sample of Galactic O-type stars separated in three groups (from top to bottom), comprising stars covering different ranges in mass and evolutionary status. Left panels: location of each subgroup in the sHRD; see also Fig. 1 for additional information about other features presented in each sHRD. Middle and right panels: Corresponding v sin i distributions for the LS and SB1 samples, respectively, within each group. In each panel, we indicate the v sin i values of 50, 150, and 300 km s⁻¹ with vertical dashed lines, for reference purposes. Similarly to Fig. 4, the stars in the LS sample, for which we only count on one spectrum, are indicated in gray in the corresponding v sin i distributions.