This volume brings together a series of studies on the nature of the dissemination of specialist knowledge in English, its various principles, conceptualizations, constructs and pragmatic dynamics, over a range of discourse genres: knowledge discourse is addressed to a number of audiences, expert and lay, in a variety of fields, legal, political, economic, institutional, academic, organizational and professional. The authors explore the use of language in the creation and diffusion of knowledge, in its transformation from being a mere repository of information, achieved through complex discursive processes. These processes use both general pragma-linguistic textual resources, and also derive from the communicative practices specific to the discourse communities in question. The studies as a whole demonstrate the multi-levels of knowledge, its very varied typology, and its dynamic nature in ongoing co-construction, maintenance and updating among heterogeneous audiences.