(a) and (e): cuts of the magnetic fields (B_x in red, B_y in green, B_z in blue and B in black) and associated hodograms in (b) and (f) across the large flux rope in Fig. 4. The cuts are along the white lines in (c). The cut in (a) corresponds to the midplane of the island where B_y sim 0 while that in(e) is offset fromthe centerline where B_y < 0. In (c) and (g) time profiles of magnetic fields ( in red, in green, in blue and B in black) and in (d) and (h) associated hodograms from switchbacks from PSP/FIELDS. The two events correspond to cases with the minimum variance magnetic field small (Nov. 1, 2018) (as in (a)) and negative(Nov. 4, 2018) (as in (e)). See the text for a discussion of the coordinate system used to present the spacecraft data. It differs from the traditional R, T, N system.