Left: J0204–1009 field. H I detected in the BCD target J0204–1009 and its three nearest neighbours, NGC 811, PGC 7892, and WISEA J020448.18–095859.0, shown with blue contours. The VLA BC-configuration H I contours are at column densities of 4.1, 8.2, 12.3, 16.5, 20.6, and 41.1 × 10²⁰ atoms cm⁻², with the first contour at 3 σ. The IDs of the galaxies are marked on a CFHT g-band image. The small ellipse in the bottom left corner indicates the size and orientation of the VLA BC-configuration 9.5″ × 7.6″ FWHP synthesised beam. The large circle shows the Effelsberg 9′ FWHP beam. Right: H I velocity field with contours separated by 5 km s⁻¹, with velocities shown by the colour scale.