The limited writing space of the SMS has created the conditions for a ludic appropriation of this mode of communication through plural and creative forms of writing. These hybrid forms meet the need for efficiency and fulfil the desire to share an original world of complicity with favourite correspondents. The discretion and reflexive distance of the written mode, combined with the speed, instantaneity and reachability of the mobile medium, explain a use value of SMS in all circumstances in which users want to avoid talking on the telephone or disturbing their environment or that of their correspondent, or in which it is impossible to talk. By allowing continuous communication without any display, the SMS participates in the construction of social rules suited to the courtesy required in public places.