exp for BG marks?

someone told me you can turn in BG marks for exp. Is this true? can you lvl by just doing BGs? if it does exist, where do you turn them in and how much exp do you get for each one?|||You used to be able to turn in 3 tokens for some XP and rep with the faction you were fighting for. I believe this doesn't exist any more.|||Yeah i have only just started playing bg again and before you could trade in 3 mark but i dont think it exist anymore....i think and i think here that u keep them and u trade them in for unique weapons :D and armour and soo on