Is the class of rules held by society to govern the conduct of its individual members. it implies the quality of being in accord with standards of right and good conduct.

I believe the answer is: morality

The purpose of morality is  to act as some sort of guidance to perform correct behavior that all 'rational' persons should do within a social group. Morality does not necessarily regulated by law, but violating it would definitely make a member of a social group the be negatively perceived by other members.