Velocity offsets of the two emission-line components relative to the stellar velocity of the host galaxy in units of their velocity dispersion σ. The two panels show the exact same points. On the y-axis (resp. x-axis), we display the relative offset of the weak [OIII] (strong [OIII]) component. In the upper panel, we compute error-bars and colour-code off-centred strong (resp. weak) [OIII] lines in green (resp. orange) and symmetric kinematics in black. In the lower panel, we encode the morphological classification with different marker styles and the BPT classification of the strong [OIII] component (see Fig. 1) with the colour.