This book contains a selection of papers presented at a Symposium on coding theory: "3 Journées sur le Codage", held November 24-26, 1986, in Cachan near Paris, France. It gives an account of the state of the art of research in France on Coding, ranging from rather theoretical topics like algebraic geometry and combinatorial coding to applications like modulation, real-space decoding and implementation of coding algorithms on microcomputers. The symposium was the second one of this type. With its broad spectrum, it was a unique opportunity for contacts between university and industry on the topics of information and coding theory.