While many past theoretical discussions on nature of social norms were centered on problem of their precise definition, I propose an analysis of peculiar character of sociological theorizing about norms which is grounded in a wider interdisciplinary context (particularly, in sociologically relevant implications from H.L.A. Hart’s and H. Kelsen’s works on law and norms) and based on systematization of principal norm-related questions which varying types of theories attempt to answer, i.e., nature of norms, social mechanisms of their support and change, analytic and empiricallybased distinctions between norms and rules and conventions, irreducible complexity of norms, etc.