In this article the author analyses forms of professional 'coding'? in information worlds. In his System of Professions (1988), Andrew Abbott provides a fertile framework for the analysis of logics of jurisdictional claims, by placing professionals' activities in an ecological framework rather than an institutional or historical dynamic. His model is used here to examine how, in a particular information world, logics of regulation by the professional 'code'? (mainly the code of ethics) are replaced by a constant activity of 'coding'? in newswork. The presentation of this activity of diffuse 'jurisdictional claims'? is based on the study of a professional quarrel between journalists, during the Santer Commission crisis in Brussels in 1998.