The document discusses the qualities needed for effective business letter writing. It identifies the key Cs of Communication that are important - Correctness, Clarity, Conciseness, and Courtesy. It explains each C in detail and how to apply them. For example, for Correctness, letters should have proper spelling, grammar, layout and accurate information. For Clarity, the message should be easily understood. For Conciseness, expressing much with few words. For Courtesy, the style and words should be considerate of the reader. The document also discusses using simple language without jargon in modern business writing to be clear and friendly.