14 April 1561, Residents of Nuremberg described an aerial battle, followed by the appearance of "something like a black spear, very long and thick" (translation: Ilse Von Jacobi). A broadsheet recorded that witnesses observed hundreds of spheres, cylinders and other odd-shaped objects that moved erratically overhead
So if you identify a UFO as a UFO, it becomes an FO, unless it has landed...then its just an O.