404, I was trying to think of a possible reason for the difference in attitudes about writing on books, but not sure why it seems to be so black and white - some people do, some people would never. I guess it must be something to do with parental/educational influence too... I did write on my A-level English books as I studied them, not thinking I'd be giving them back, and it was so awful when they were duly collected in at the end of the two years...because the book had become mine. Haven't written on anything else, I don't fold the pages either - it's just unnecessary.