"The University is very concerned about behaviour outside exam venues such as Examination Schools and Ewert House. You must not throw or spray foods or fluids (e.g. champagne/fizzy drink, flour, eggs, fish or squid, shaving foam, silly string) because they create a major hazard (the pavements become extremely slippery) and doing so is viewed very negatively by the Proctors, the City Council and the Police. Other substances which are not hazardous (e.g. confetti, glitter) are considered litter and for that reason are also not allowed."