The F Word is used in a deleted scene in A Tale Of Two Springfields, where The Who say "F[rink] You Marge, on the 4th disc, and since this is also accessible on the 1st disc, that means that only the 2nd and 3rd discs are family friendly.
"kids, here's the two discs from Season 12."
"I thought there were four discs."
"There are, but two of the discs are Adult Material."
(Homer voice imitating a child) "Well, if I can't watch it, be sure to watch it for yourself."
"kids!"
So what's on the future Simpsons DVDs, hardcore porn?