Top panels: velocity of the wing against FWHM of the core component for both samples, regular sources in the left and outliers in the right. Bottom panels: velocity of the wing against FWHM of the wing for both samples, as before. RQNLS1s are indicated by red circles, RLNLS1s are indicated by blue squares. The black filled rectangles represented in the boxes at the upper left corner of each diagram illustrate the size of the average uncertainty range of our measurements.