Radio spectra for different radio-associated cases: a) event of 18 June 2000 with type III/II radio association; b) event of 11 April 2004 with type III association; c) event of 25 July 2004 with type III/IV-c association; d) event of 16 June 1998 with type II association; e) event of 17 April 2002 with type IV-c association; and f) event of 20 August 2002 with “no inferred” radio association. In each panel, the vertical lines have the same meaning as in Fig. 1.