This paper considers the modes of development of a local system of law and order. It is based on empirical research on the space framework of a railway station in France. It shows how the identity assigned to homeless people is built within this physical and symbolic space (and its multiple functional subspaces). The identity assigned to the homeless by various actors of the station is relatively fluid. Flexible cognitive categories evaluating the level of deviance/conformity are used by the actors. These classifying operations, never completely stabilized, shed light on how the suitable standards are constituted collectively for a public space and how these standards may be used as a basis for the deployment of various modes of social reaction.