This document discusses sustainability indicators used by tourism businesses to measure their environmental and social performance. It provides examples of indicators used by Accor Hotels, a major international hotel chain, to track metrics like water and energy consumption, waste management, and the number of hotels implementing the company's environmental charter. Accor gathers data monthly from its hotels around the world, analyzes the results to compare performance across regions and brands, and reports the findings publicly in its annual sustainability reports and internal publications. The use of quantitative indicators allows Accor to monitor improvements, motivate the spread of best practices, and work towards its sustainability objectives over time.