The author begins this thorough discussion of a neglected but vital topic by examining the real purpose of defensive signalling, and the basic kinds of signals that are available. He goes on to recommend a comprehensive set of signalling agreements, and analyzes more complex situations in the light of these agreements. Most of the chapters are followed by a quiz, and the answer to each signalling problem includes a full 52-card diagram to demonstrate the effectiveness of the recommended signal. The book finishes with a chapter that looks at the signalling methods of eight world-class pairs, with examples of their methods in action. A book any player who is looking to improve will want to read.