Rules are, first of all, constitutive expressions. They (often implicitly) tell us what exists, in what measure, and in what relation.
Also there are regulative rules. Often more formal and explicit, they regulate social behavior inside the structured, prescribed (constituted) reality by specifying guiding and sanctioning human activity in particular ways.
Rules shape and facilitate dominant ideologies by linking ideological and hegemony with various forms of authority in symbolic representation and social practice.