[E. Pluribus Unum]

By definition a UFO is "unidentified."

Merely being unidentified does not prove extraterrestrial origins.

[Spok]

Exactly. Still unidentified. What’s new?

[dr_lew]

Plus, it should be a “flying object”, which requirement seems often to be overlooked, as any sort of apparition or perception is admitted, seemingly without qualification.