Information
NL Nocturnal Light | All objects sighted at night from a greater distance
DD Daylight Discs | All objects observed during the day from a great distance
CE I Close Encounter of the First Kind | Close observation up to a distance of 150 meters. No interaction with the environment
CE II Close Encounter of the Second Kind | Close encounter with interaction with the environment in the form of psychological or physical effects
CE III Close Encounter of the Third Kind | Close encounter and additionally the observation of occupants or beings in and outside the observed object. This also includes contact reports.
CE IV Close Encounter of the Fourth Kind | Close Encounter with observation of occupants and additional abduction of the witness by the beings into the object
CE V Close Encounter of the Fifth Kind | Close encounter in which the witness is permanently injured or killed
CE VI Mutilation of humans or animals by extraterrestrials.
RV Radar / Visual | An object that has been sighted both on radar and visually
Hendry Classification System
IFO | Clearly identified UFO as a natural cause
NEAR IFO | An object that possesses characteristics of a natural object but cannot be clearly identified as an IFO
Problematic UFO | An object that exhibits anomalous characteristics, but these can also occur in conventional objects under extreme conditions, and therefore cannot be clearly identified
Good UFO | An object that exhibits so many anomalous characteristics that a conventional explanation can very likely be ruled out
Best UFO | An object that exhibits so many anomalous characteristics that a conventional explanation is clearly ruled out