In the under cover scene with Hogan and Col. Klink, the stained glass behind them forms the shape of the Star of David. Shout out to the Jewish actors in this show.
Near the end when Newkirk tosses the envelope to Hogan past Klink, Hogan tells Klink, "Tinker to Evers to Chance is the play. You're only Evers, I'm Chance." Hogan is referring to the famous double play combination of the 1908 World Series champion Chicago Cubs.
HM Prison Pentonville (informally "The Ville") is a Category B/C men's prison, operated by Her Majesty's Prison Service.
Wilhelm II (1859-1941), the German kaiser (emperor) and king of Prussia from 1888 to 1918, was one of the most recognizable public figures of World War I (1914-18).
A Burgermeister is chairman of the executive council (or cabinet) in many towns and cities in Germany.