[Horst Weber]

Hi chicoartist !

Those terms were given by the German Luftgaukommando Office, which was responsible for everything, what happened on the ground and came from the air.

J-report means : Jäger = pursiut aircraft
KU-report means: Kampfflugzeug USA = Bombing Aircraft (USA)
KE-report means: Kampfflugzeug England = Bombing Aircraft England (RAF)

Very quick postwar, those reports were send to the U.S. for evaluation purposes. In the States, the originals are still on stock in the National Archives. These files never had an access postwar to German historical evaluatins and discussions and are still in U.S. archives.
Fortunately, most of those reports are added to the respective MACR, but not all.

All the best !

Horst Weber