Every year, I am afraid to say, seems to harbour at least one student who thinks that he or she can get around the Wizarding Examinations Authority's rules. I can only hope that it is nobody in Gryffindor.
-- Professor McGonagall (OP31)
Anti-Cheating Spells and Charms are cast on quills and examination papers before exams at Hogwarts.
References from the canon
- Cast on quills during Harry's First Year (PS16).
- McGonagall tells the Gryffindors before their O.W.L.s that "the most stringent anti-cheating charms have been applied to your examination papers. Auto-Answer Quills are banned from the examination hall, as are Remembralls, Detachable Cribbing Cuffs and Self-Correcting Ink ..." (OP31)
From the Web
"Anti-Cheating Quill" on Harry Potter Wiki
"Anti-Cheating Spell" on Harry Potter Wiki
"Anti-Cheating Spell Trading Card" on Harry Potter Wiki