Radio event associated with the flare–CME on 9 October 2021. Panel (a) shows the full radio spectrum from the Earth vantage point, including both ground-based and space-borne observations in the range 10 GHz to 20 kHz. The different types of radio bursts are marked on the spectra with their respective abbreviations. Panel (b) presents a zoomed-in view of the decimetric-metric-decametric observations that showcase different structured radio emission, such as herringbones and a stationary flare continuum. The details of the structured radio emission, i.e. type II herringbones(TII(HB)) and a very narrow-band wavy type II burst (TII(W)), are presented in panels (c1) and (c2), respectively. The units across all panels are the same. The vertical axis is the frequency in megahertz (MHz), and the horizontal axis is universal time (UT).