This production has not been approved, endorsed or authorized by the Federal Bureau of Investigation. (appears in the end credits)
Occasionally, the phrase "The Truth Is Out There" in the opening credits has been changed to something else, for example "Trust No One" or "Apology is Policy".
In the main title for the ninth season, a piece of paper flashes across the screen listing "FBI Contacts: Witnesses and Contributors." The names on the list are screen names of the series' on-line fans. For episodes #9.01-#9.11, the names were randomly picked from various X-Files message boards. For episodes #9.12-#9.19, the names came from contest entries.
The opening credits of the first 7 seasons include an extreme close-up of an eye blinking. In the 8th season credits, the eye belongs to 'Gillian Anderson (I)'.
At the end of the credits, the logo for Ten Thirteen Productions is shown, and a child's voice says "I made this!"