In this paper I examine discourse in five letters written by executive members of a resident's association in the city of Brasilia, by integrating Critical Discourse Analysis and the New Literacy Studies. These letters were part of a campaign from the association to prevent students of a nearby college from parking their car in the residential street, since the overload of parked cars made difficult the flow of vehicles. A case is made on the efficacy of the discursive and semiotic resources drawn on the letters to have community aims met.