This article analyses an ethnographic sequence around the different ways of occupying places to sit in a public space in the increasingly gentrified La Chapelle area in Paris. The description of the compromises between be different elements involved through the perspective of young people using this space allows us to demonstrate the different ways young people are categorised, and the different categories they produce themselves to justify and find their place in this changing space. The empirical approach allows us to explore existing studies on gentrification, providing nuance and complexity to studies focused on dynamics of eviction and competition for space. The modalities for managing the sharing of public space pave the way for a hypothesis on “de facto” management which takes the form of “infra-politics” of urban public space.