Their pattern of relations, abstracted from the institutions in the position, defines a status with a role-set, a set of relations with other statuses. The system can be described as interrelated positions or, at a higher level of abstraction, as role-set interlocking statuses. This image is familiar in Granovetter's weak metaphor, Freeman's betweeness centrality, Cook and Emerson's model of exchange power, model of structural autonomy, and structural hole theory of competition. The general idea is demand. An institution who is the object of relations has something of interest to everyone sending the relations.
Some institutions have a lot of it.
Others have very little. This vertical axis of organisation is broadly conceived and encompasses the prominence concepts of centrality, prestige, demand and value. The relation cost increases with the difficulty of managing a relationship independent of other relations. Network constraint increases from 0 to 1 with the extent to which contacts within and between contact clusters are bound by exclusive relations to one another so it is difficult to play them against one another.