The origin of the X-files is revealed. Unsolved cases were filed under "U" until too many were in there, so they started putting them under "X." A case was given an "X" by the director's office.
The part of Agent Arthur Dales is played by Darren McGavin, who portrayed the title character Carl Kolchak in Kolchak: The Night Stalker (1974). Chris Carter has stated that his love for Kolchak: The Night Stalker and other TV shows that dealt with the supernatural were the inspiration for The X-Files. Carl Kolchak was very similar to Fox Mulder in that he regularly ventured into situations trying to expose the supernatural and beings that are characterized as monsters.
This is written as a tribute to Howard Dimsdale, a screenwriter who was victimized by Hollywood blacklist in the 1950s and who later got work as a screenwriter under the alias "Arthur Dales."
This episode was bleached in post-production to give it a more vintage feel.
The lack of Mulder and Scully in this episode is due to the fact that David Duchovny and Gillian Anderson were doing reshoots for The X Files (1998) in Los Angeles.