The consumption of digital services has increased and has negative effects on the quality of life at work and even on the health of employees. Some solutions, such as charters, have been considered to address these problems and standardize practices. However, these solutions are often rigid and not aligned with work practices. As a result, they are little or not used at all. Faced to these findings, we are interested in studying existing practices of defining digital communication conventions in an organization. This poster presents an ongoing case study within a French national public agency where most of the agents are nomadic workers. We are intended at involving these workers so that they can collectively negotiate conventions and dynamically handle these conventions to make possible an evolution of their work practices.