remote station's callsign
The perceived clock differential between the local station and remote station, in seconds.
remote station's Maidenhead grid
WSJT-X client name
Whether the decode is new or replayed
whether the decode came from playback of a recording
power in dBm
Local station's perceived signal to noise ratio
Clock time in milliseconds since midnight
The decode message is sent when a new decode is completed, in this case the 'New' field is true.
See WSJT-X source.