What's your favourite ever pupil graffiti or textbook alteration?
I have two: one was by a member of my tutor group (year 9!) and was written on the wall by my desk - it said, 'I shagged XXXX in your chair miss, sorry about the stain.'
The other is an alteration to Much Ado, where Don John no longer says that he would 'rather be a canker in a hedge than a rose in his grace.' No, Don John would much rather be a wanker in a hedge.
Have you come across any gems?