The World Reference Base for Soil Resources (WRB) is an international soil classification system endorsed by the International Union of Soil Sciences. It classifies soils into Reference Soil Groups (RSGs) based on diagnostic horizons, properties, and materials, emphasizing soil formation processes and global soil distribution. The WRB is designed to provide a common language for global soil studies and is widely used in international soil research and environmental management. Source: IUSS Working Group WRB (2015). World Reference Base for Soil Resources 2014: International Soil Classification System for Naming Soils and Creating Legends for Soil Maps