Since their original airings, the four episodes from season six have never been shown as a rerun since.
The Ashleys were inspired by the Heathers of the cult movie, Heathers (1988).
Although, Gus' first appearance was in season one, episode two, "The New Kid", he was not seen in season one, episode four, "The Great Jungle Gym Standoff". This has sparked speculation that this episode took place before "The New Kid".