At the center of the personal computer and Internet revolutions, Vallee became a venture capitalist and served as an early-stage investor and director of many companies.
Vallee had a long-term private interest in unidentified aerial phenomena, stemming from a sighting from his home in May 1955. In 1961, while on the staff of the French Space Committee, Vallee witnessed the destruction of the tracking tapes of unknown objects orbiting the earth. Using his computer skills, Vallee collected and analyzed thousands of UFO sightings in the 1960's, resulting in two books, Anatomy of a Phenomenon in 1965, and Challenge to Science in 1966. He provided his database to the Condon Committee, but found them impossible to work with.
By 1969 he came to the conclusion that UFO's were not nuts-and-bolts hardware delivering visitors from other planets. Instead he found that they had much in common with creatures and events in mythology, including modern cults, religions, cryptozoology and psychic belief systems. He believed something was happening, but that it represented manifestations of a multidimensional universe that coexisted with our own. This conclusion was documented in a further series of books, running from Passport to Magonia in 1969 through Revelations : Alien Contact and Human Deception in 1991. These books did not make him popular with mainstream UFO enthusiasts, who were wedded to the idea that UFO's were spaceships delivering beings from other planets within our own dimension. At the same time they did not persuade scientists, who did not consider the phenomena worth spending time on.
Vallee developed a system for coding UFO's that consisted of four categories of sightings: Anomalies, Flybys, Maneuvering Aircraft, and Close Encounters. Vallee's system was useful in that it differentiated between flybys (which could be conventional aircraft, meteors, satellites, migrating birds) and maneuvering objects less likely to fit in these categories. It may have been more useful than the Hynek system, but Hynek's codes are in more general use today.
Each of Vallee's categories was assigned a number from 1 to 5 to indicate the depth of the experience:
|AN||AN1:Anomalies which have no lasting physical effects. i.e. amorphous lights, unexplained explosions. - Equivalent to Hynek code NL or UX, strangeness 0||AN2: Anomalies which do have lasting physical effects. i.e. poltergeists, materialized objects, areas of flattened grass, corn circles. - Equivalent to Hynek code TC, strangeness 0||AN3: Anomalies with associated entities. i.e. ghosts, yetis, spirits, elves and other mythical/legendary entities. - Equivalent to Hynek code CE3, strangeness 0||AN4: Witness interaction with the AN3 entities. i.e. near-death experiences, religious miracles and visions, out-of-body experiences. - Equivalent to Hynek code CE3 or CE4, strangeness 9||AN5: Anomalous reports of injuries and deaths. i.e. spontaneous human combustion, unexplained wounds as well as permanent healing that results from a paranormal experience. - Equivalent to Hynek code AM or CM, strangeness 9|
|CE||CE1: UFO comes within 500 feet of the witness, but no after effects are suffered by the witness or the surrounding area. - Equivalent to Hynek code CE1, strangeness 5||CE2: A CE1 that leaves landing traces or injuries to the witness. - Equivalent to Hynek code CE2, strangeness 5||CE3: Entities have been observed on the UFO. - Equivalent to Hynek code CE3, strangeness 7||CE4: The witness has been abducted. - Equivalent to Hynek code CE4, strangeness 9||CE5: CE4 which results in permanent psychological injuries or death. - Equivalent to Hynek code CE2 or CE3 or CE4, strangeness 9|
|FB||FB1: A simple sighting of a UFO traveling in a straight line across the sky. - Equivalent to Hynek code NL or DD, strangeness 2||FB2: FB1 accompanied by physical evidence. - Equivalent to Hynek code CE1 or CE2, strangeness 5||FB3: A fly-by where entities are observed on board (rare). - Equivalent to Hynek code CE3, strangeness 5||FB4: A fly-by where the witness experienced a transformation of reality into the object or its occupants.||FB5: A fly-by which the witness would suffer permanent injuries or even death.|
|MA||MA1: A UFO has been observed which travels in a discontinuous trajectory. i.e. vertical drops, maneuvers or loops. - Equivalent to Hynek code NL or DD, strangeness 4||MA2: MA1 plus any physical effects caused by the UFO. - Equivalent to Hynek code CE2, strangeness 5||MA3: MA1 plus any entities observed on board. i.e. the airship cases of the late nineteenth century. - Equivalent to Hynek code CE3, strangeness 5||MA4: Maneuvers accompanied by a sense of reality transformation for the observer. - Equivalent to Hynek code CE4, strangeness 9||MA5: A maneuver that results in a permanent injury or death of the witness.|
Vallee also assigned what he called an SVP code to assess the quality of the report. This consisted of three digits, each with a range of 0 to 4: