The 10 Dos and 500 Don'ts of Knife Safety is a book published by the Junior Campers. It is used to teach members how to handle knives safely.
When Bart joined the Junior Campers, he was impressed by the pocketknives the members got to carry and wanted one for himself. Troop leader Ned Flanders, however, told Bart that he couldn't have a knife until he read the book and passed a knife safety test. Bart scoffed at the book, but relented and decided to read it after he saw how useful knives were in everyday situations.
The book's instruction is very simple: "Don't do what Donny Don't does." Donny Don't is shown doing things such as brushing his teeth with a knife, using a knife in a slingshot, and menacing a sleeping cat with his knife. Bart, reading the book, lamented that "They won't let you have any fun", but he finished the book and passed the knife safety test. Flanders then issued Bart a rubber training knife and told him that he had attained the rank of "Pussy Willow".
Disgusted with the rubber knife, Bart nearly quit the Junior Campers, but decided to stay when Flanders announced that the next lesson was how to trap wild animals.