Lieutenant John Doe is a fictional character often used in military training and legal contexts to represent an anonymous individual. The name "John Doe" serves as a placeholder for a male whose true identity is unknown or must be kept confidential. This practice helps maintain privacy while discussing various scenarios. In military settings, Lieutenant John Doe may be depicted in training exercises to simulate leadership and decision-making under pressure. His character can also be used in legal cases to illustrate issues related to military law, ethics, and the responsibilities of officers within the United States Armed Forces.