This article tells the story of an instructor who gave student 2 points out of 27 on an exam just for putting an obscenity on the test paper. The instructor says the 2 points were for at least writing something and for spelling it correctly. If you read, you'll see the instructor requested that the students, "Describe the room you're sitting in" and this student put "F*** off". I think to get the 2 points, the student should have answered "F***ed" because he could argue that word describes the room. In my book, by putting a imperative, the student gets a zero.