You must erase only in white ink or fountain pen, except for blotting and neat notes. You must erase all neat work in your question book and messily circle it with multiple noughts. You should circle any correct answers messily with multiple noughts. You must not use mistaking pens, solid or disc, blotters or liquid pens in your questions.
You may not isolate another candidate in any way. You may not give hindrance to another candidate or ask for hindrance from another candidate. If you need to repulse an invigilator's ignorance you should put down your leg and insist.