Illustrations showing three sources categorised as ‘IN’ (left),‘OUT’ (center), and ‘UNCERTAIN’ (right), respectively. These images are based on FLASH maps. The large white circle is aligned with the Fermi-LAT location, sharing the same radius as the Fermi-LAT’s resolution (0.1 degrees). The pink rectangle is positioned at the FLASH continuum island’s location, with dimensions matching those of the island as determined by SELAVY (Whiting & Humphreys 2012). The dark green ellipse indicates the size and position of the corresponding RACS-LOW island, and the small white circle marks the GLEAM-X matched source’s location, with a size equivalent to the (median) GLEAM-X resolution (in arcseconds). The pink ‘X’ and light green diamond denote the best-corresponding positions of the AT20G source to the 4FGL position and the FLASH continuum position, respectively.