The reason Bruce Willis is not credited is because he violated SAG rules for acting in this film for no money. He appeared for fun and as a favor to Quentin Tarantino, and acting for free violated SAG rules. SAG agreed not to sue Willis if his name was not included in the credits.
Just before Ted answers a call from The Man in "The Misbehavers", a package of Red Apple cigarettes is visible near the switchboard. This fictitious brand of cigarettes features in other Quentin Tarantino films.
Quentin Tarantino's "A Band Apart" Production logo at the beginning of the film shows 'Tim Roth's "Mr. Orange" unzipping (shedding) his character from Reservoir Dogs - Wilde Hunde (1992) and becoming the bell hop character for Four Rooms (1995).
Robert Rodriguez and Antonio Banderas shot their segment one week after wrapping up the filming of Desperado (1995).
Quentin Tarantino: [long take] When Ted first enters the Penthouse suite (when Angela says "The Bellboy's here"), the camera goes all around the suite to introduce Ted (and we, the audience) to Chester, Angela, Leo and Norman. It also continues through Chester's praise of Cristal and Jerry Lewis, his temper tantrum, and his self-congratulations about the success of his movie, ending with Norman lighting Angela's cigarette. All in a single take.
Quentin Tarantino: [GM motor vehicle] Reference to a 1964 Chevelle Malibu convertible, previously seen in Pulp Fiction (1994).