Face-on view of TNG-Cluster radio relic systems that may be confused as radio halos. We plot the radio surface brightness (top) and the X-ray surface brightness map overlaid with the radio contours (bottom). The dotted circle marks the R_500c of the cluster. In these projections, the radio relics exhibit a radio halo-like appearance. However, differently from the latter, they are characterized by a significant drop in surface brightness at their edges and by a radio emission that is not correlated with the X-ray emission.