I'm trying to operate a WSPR beacon for a special event station (N1D). It appears that the decoder in WSJT-x does not accept the use of a three letter call sign. The only spots I am getting are from (older?) decoders such as what is built into a KiwiSDR receiver. Wonder if this limitation is documented anywhere? Of course, the workaround would be to append a special suffix to the call sign.