This volume comprises contributions originally presented at the 15th European Symposium on Languages for Special Purposes held at the University of Bergamo on 29 August 2 September 2005. The volume is divided into four parts Approaches to Terminological Theories Terms in Discourse Knowledge Elicitation Ordering and Management Term extraction and terminographical work. The research presented in the various contributions to this volume clearly indicates that terminology as an inter and transdisciplinary field of knowledge is firmly developing its theoretical foundations and practical applications in accordance with and within the framework of its overall goal to ensure and to augment the quality of communication with professional content.