BRGS has brought in a couple of supply teachers, either on days when a lot of teachers are on a trip or when a teacher is ill and they cover their lessons for a few months.
Luckily many supply teachers don't understand the whole Penalty Point system, and therefore cover lessons with them are usually a doss. If you do anything wrong then it is usually followed up with a menacing "do you want me to sign your planner?!" and then wondering why this has no effect.