This goes for all bands but on 20M we have neighbors using Packet on 14.105MHz LSB. Slots 3, 4 and 5 would be a potential QRM issue. I plotted the occupied bandwidth of each of the modes and slots used, along with the Guardbands. Slots 1 and 2 are fine if they are clear. Occupied freqs below are USB.
Seems to be a RTTY contest? And it's more than just 20M.