It's worth noting that at my school there were also the
prefects taken from all
FastEddie's well defined groups. They came roughly in order from
sports people, smart chatty types and
useful geeks (for
library duties etc).
Prefects could easily be elevated in status or rejected as teacher's pet depending on use and abuse of their priveliges (they were nearly all door monitors). This adds a new dimension the the heirarchy, unlike the position of hall monitor which I believe is universally resented.
Of further note is the fact that my school only went up to age 16, and after GCSE exams we either left school or went to a separate college. This, coupled with the fact that we all wore school uniform and had strict rules about make-up etc, meant that nobody really expressed themselves until after school. However, this was made up for by my very relaxed college, an excellent first step towards university with most social types represented and - pleasingly - no uniform.