To OP: Square means Unknown or Ambiguous. So if something has no iff reply and no other donor is confirming the same lack of reply the trackfile will remain as unknown and HUD will show square. If contact has more than one lack of reply, for instance you and a donor or you and an awacs, the hafu will be hostile and the HUD will show diamond with hat above. If contact replies positive to M4 and you are "alone" hafu will be friendly and HUD will be unknown (problem 1). If contact has more than one positive M4 reply, for instance you and an awacs, the hafu will be friendly and HUD will be unknown with a half circle above indicating friendly. Here is where it starts to smell odd. Like I replied to Santi, when no donors are around but the hornet knows it is a friendly (positive M4), then the HUD won't agree and will say "hey, you think it's friendly, well I don't think so", LOL.