Explaining about marks:
People that have higher than villager post
have marks on their face.Marks are different and giving their owners powers.Owners can mark their lover and also servants.Family of the owner have marks on cheek and servant on their neck.
Children getting marks when they born but if someone with mark adopt a child,they can get mark on cheek from their step-father/mother.
Also two owners of marks can create unity of two families by uniting their marks.Usually the unity happens with wedding of two owners of marks and other person(without a mark)

I hope you understood the AU;)