Many Ufologists believe that the Black-triangle UFO is a highly classified spy plane called the Aurora. This craft is capable of travailing at incredible speeds and may contain extraterrestrial technology.

in the Nazi concentration camps, the black triangle (equilateral, worn point down) was used to mark "undesirables," such as prostitutes, the mentally ill, and the retarded. Lesbians in the camp probably would have also worn the black triangle, although there is some debate about it. It is sometimes worn as a pride symbol by lesbians.

A symbol in the shape of an inverted triangle adopted by lesbian culture in remembrance of the lesbians who were forced to wear a black triangle and were killed by the Nazis in Europe.