Shop assistants may be made to wear a uniform, there may be limits on the kind of make-up they can wear and that may actually be quite clearly stated in the definition of their r le. College lecturers have a good deal more freedom to determine their appearance, indeed even to determine how they use much of their time. On the other hand, customers expect as a minimum to be served and students expect to be taught. There are limits beyond which a lecturer cannot stray without giving students the feeling that they are not being 'taught properly'. These expectations circumscribe the personal interpretation which the individual performer can bring to the r le.
Social systems affect how, why, to and from whom, and with what effects communication occurs.
For example, our social position increases the probability that we will talk to people in equal or adjacent positions and lowers the probability that we will communicate with those in different positions. People tend to stick to communicating with members of their own class, age group or job. There are working class pubs, middle class wine bars, student discos. The system determines the frequency of communication for individuals. There is a system style, a characteristic way in which members of a given system encode and decode messages.