One of my favorite parts of New York Times movie reviews are the sardonic summaries that explain how each film earned its particular MPAA rating.
For example, at the end of
A.O. Scott's review for the zombie flick "28 Weeks Later", we learn:
"28 Weeks Later" is rated R (Under 17 requires accompanying parent or adult guardian). Rabid zombies feast on living flesh, which causes their potential victims to utter an occasional obscenity.