Easter egg: On Disc 2, go to trailers, and select Theatrical Trailer #3. While the trailer is playing, input the following numbers in order (slowly): 5 6 5 3 7 (JOKER). The trailer will restart and show a modified version of the original trailer, with Joker scribbling all over it. This is a reference to the marketing campaign promoting the movie, as fans who completed the entire set of events were greeted with the third "The Dark Knight" trailer, modified by the Joker.