A peculiarity of Scottish FA law bans its fans from entering the ground with Thermos flasks. This created an annoying paradox in which Scottish fans wished to drink Bovril at half-time to prevent frostbite, and yet were unable. Luckily, it can purchased inside the ground in plastic or, more commonly, polystyrene cups. When you think about it, it makes sense. They might hide knives, offal, bits of glass or fried stuff in there. Lethal.