GLOSSARY
UAP glossary: the terms in the declassified files.
The vocabulary you will meet across these documents — official acronyms, sensor jargon and the words the files use for what they could not identify. Defined for readers, not for specialists.
- UAP — Unidentified Anomalous Phenomena
- The current official term, adopted to replace "UFO" and widened beyond aircraft to cover anomalous objects reported in the air, in space, on water and underwater. Using it implies nothing about origin: it means an observation that has not been resolved.
- UFO — Unidentified Flying Object
- The term used throughout the older files. In documents from the 1940s to the 1990s it is simply the working label of the day, and is often shortened in reports to "flying disc" or "flying object".
- PURSUE
- The programme under which the U.S. Department of War publishes declassified UAP material in batches on war.gov/ufo. It is the source of every record in this archive.
- AARO — All-domain Anomaly Resolution Office
- The U.S. Department of War office responsible for detecting, identifying and resolving anomalous phenomena reports. In recent records, the "AARO Comment" is the office's own assessment of what the material shows.
- Project Blue Book
- The U.S. Air Force investigation of UFO reports that ran from 1952 to 1969, preceded by Project Sign (1948) and Project Grudge (1949). Much of the mid-century paperwork in these releases belongs to that chain of investigations.
- FLIR — Forward-Looking Infrared
- An infrared sensor carried by military aircraft that images heat rather than visible light. In FLIR footage a bright object may be hot rather than luminous, and the display often shows "WHT" or "BLK" to indicate which polarity is being used.
- VIRIN
- The Visual Information Record Identification Number, the unique identifier the U.S. military assigns to an official photograph or video. It is the reference to quote when citing an image.
- DVIDS
- The Defense Visual Information Distribution Service, the public platform that hosts and serves official U.S. military imagery and video. The video files in this archive stream from it.
- Redaction
- The removal of information before release — names, sources, methods or the identity of witnesses — usually appearing as black bars or blank space. Redacted is not the same as illegible: one is a decision, the other is decay.
- Declassification
- The formal process by which classified material loses its restriction and can be released. A declassified document is public, but it may still be released with redactions.
- FOIA — Freedom of Information Act
- The U.S. law that lets anyone request records from federal agencies. Many of the older files in this archive carry the stamps and case numbers of earlier FOIA requests.
- Parallax and sensor artefact
- Two of the most common ordinary explanations for anomalous-looking footage: apparent motion caused by the movement of the camera itself, and shapes produced by the optics or processing rather than by an object. AARO assessments cite them frequently.
- Unresolved case
- A report closed without an identification. It means the available data was insufficient to determine what was observed — not that something unexplainable was confirmed.
- Incident date vs. release date
- Two different dates that appear on every record here: when the event was reported to have happened, and when the document about it was made public. They can be seventy years apart.