* ActorSharedBackground: Hacker, Sir Humphrey, and Bernard share birth dates (and dates of death where applicable) with the actors who portrayed them.
* HeyItsThatGuy: The caricatures and TitleDrop in the opening credits were created by Gerald Scarfe, whose style you might recognize from [[TheWall a certain rock & roll album]].
** Recurring character Sir Ian Whitchurch (or Whitworth) was played by John Barron, who played CJ in ''Series/TheFallAndRiseOfReginaldPerrin''.
** Another recurring character, Sir Desmond Glazebrook, is played by Richard Vernon, who is probably better remembered these days as the original [[Radio/TheHitchhikersGuideToTheGalaxy Slartibartfast]].
** The commissioner of the Metropolitan Police is [[Series/DoctorWho Brigadier Lethbridge-Stewart]].
** Sarah Harrison is (depending on your fanbase) either Miss Minchin in ''Literature/ALittlePrincess'' or Ahme from ''{{Film/Help}}''.
** Commander Forrest of Special Branch was played by [[Series/TheGoodies Graeme Garden]].
** In the 2013 series, the Deputy Prime Minister is [[Film/HarryPotter Hagrid]].
* ThrowItIn: The moment in "The Official Visit" where Bernard's briefcase falls open and lets his files spill out on the station platform was unscripted -- in fact, Derek Fowlds actually said "oh, shit!" when it happened, which somehow made it into the finished episode (probably because it was only just audible over the noise of the trains).