X-Files
From Multiversal Omnipedia
The term "X-Files" is a designation for files in the FBI archives that involve cases with unexplained phenomena. They were originally filed under 'U' for 'Unsolved', but when space in 'U' ran out they were moved to 'X'. Many FBI agents have worked on the X-Files, most notably Special Agents Fox Mulder and Dana Scully.
