Cases of individuals taken inside a spacecraft (a UFO) for medical examinations, tests and other traumatic experiences. A whole bibliography has been written by pro-extraterrestrial hypothesais researchers like Hopkins, Jacobs, Mack, Turner. Skeptics point out the symptoms are nothing but of psychological origins.The phenomenon is complex and not always related to UFO activity.

Alien pilots, following the Hynek classification.

Aerial Phenomena Research Organitation, created and directed since 1952 in the USA from Coral and Jim Lorenzen.The first american civil study center on UFO, disappeared after 36 years of activity.

Bug-Eyed Monsters. Ray Palmer filled the Amazing Stories magazine, bought by Ziff-Davis Publishing Company in 1938, with non fiction stories, semi-science and parascience, along with such short stories about BEM, who ruled the world from their coves.

Blessed Virgin Mary, referred to the holy apparitions of Virgin Mary as an animated entity.

Sometimes caused by UFOs flying low in the air thanks to electromagnetic interferences.

British UFO Research Association, main English study centre in the United Kingdom.

Centre d'Etudes et de Recherches sur les Phénomènes Aérospatiaux, a French private centre started in 1989 by Bernard Hugues, Gérard Roméo et Patrick Teboul at Marseille. The C.E.R.P.A. organizes a four-day informative UFO days in Marseille each year. In particular, the 1995 edition was remarkable. From 1990  on, they publish 8 issues of Aérospatial, Météorologie, Astronomie and in 1996 the first issue of Univers OVNI as well.

Communications Instructions for Reporting Visual Intelligence Sightings. In use for each urgent secret report addressed to the Air Defence Command.  This procedure is mandatory in case of UFO sighting by the Air Force.

Control Reporting Center. As part of the North Atlantic Treaty Organization, C.R.C. aims at detecting any airships over protected skies, identifying them as friends or enemies and eventually alerting the air forces.