Data from Myserlis et al. (2018) for OJ 287. (a) Total flux density (Stokes I), (b) linearly polarized flux density, (c) EVPA. The 180° step at MJD 7492 in (c), at 10.45 GHz, is introduced to show that the EVPAs at 8.35 and 10.45 GHz are closely similar after that date. The five stars are 180° below the corresponding 8.35 GHz triangles and are discussed in the text. Events A, B, and C are described in the text. MJD 7400 corresponds to 12 January 2016.