Chapter three discusses the principles of business communication, emphasizing the importance of careful planning, the 7Cs (completeness, conciseness, concreteness, clarity, correctness, consideration, and courtesy), and specific guidelines for effective writing. Each principle is elaborated upon, offering strategies to ensure messages are complete, concise, clear, correct, and considerate, ultimately improving communication effectiveness in various formats. The chapter underscores that understanding the recipient's perspective and employing a 'you-attitude' enhances positive engagement and clarity in communication.