1.
Duel mode specific rules
No following or face-hugging the other duelist before the duel countdown has ran out - either hold your starting position or back-pedal if you want some distance between you and your opponent
2.
No random kick/ban polls. Always specify reason before starting a poll
NOT OK: poll-kicking someone because you don't like his playstyle
also, atrocs, you should think about this one :
"first rule of em all: common sense"
~ chadz
source : http://forum.melee.org/announcements/official-server-rules/msg44544/#msg44544