Skewness (defined as , where h ₃ is the third coefficient of the Gauss–Hermite function) of the super profiles derived from the opposite sides of the major axis. PA+90° side: position corresponding to a position angle (PA) of 90° with respect to the PA of the receding major axis. PA+270° side: position corresponding to a PA offset of 270° from the receding major axis. The three outlying galaxies are, from left to right, NGC 1569, DDO 53, and NGC 3031. The plus and minus signs represent the signs of the skewness parameters. Symbols follow Figure 8.