This chapter presents the requirements from the 11th edition of the ICC Advertising and Marketing Communications Code, developed by the International Chamber of Commerce (2024), which represents the most detailed and comprehensive guideline on how marketers can communicate sustainable customer value. The chapter outlines the key principles that should govern responsible marketing practices in advertising, sales promotions, sponsorship, data-driven marketing, environmental marketing, and marketing to children. It emphasizes the importance of legal, ethical, and honest communication, social and environmental responsibility, transparency, and evidence-based claims. The chapter also discusses the risks of greenwashing, the need for substantiated environmental claims, and the special considerations required when marketing to vulnerable audiences such as children and teens. By adhering to these principles, businesses can foster consumer trust, promote fair competition, and contribute to a responsible marketing environment that benefits both companies and society.