No Hacked Clients.
No Transparent Texture Packs.
No Advertising other servers.
These rules go along with the role-play, and aren't "ban-worthy."
No Weapons - Swords, Bows, Flint and Steel, Potions, etc are not allowed. If a guard sees you with one of these, you have 5 seconds to drop it or risk a jail of 5 minutes or death!
No Camping - Camping a player or any other Non-PvP areas will get you jailed.
No PvP Abuse - Hitting from a Non-Pvp area or pushing someone out of an area will get you jailed.