What is the internationally recognized system, developed primarily by Finnish and German scholars, used to categorize and index thousands of traditional folktales, ballads, and myths based on their plot similarities (Type)? This system is commonly abbreviated using its initialism.

💡 Explanation:

The Aarne–Thompson–Uther (ATU) Index is the standard scholarly classification system for folktales. It organizes tales into types (e.g., Tale Type 510, ‘Cinderella’) to aid in comparative study. It was originally developed by Antti Aarne and later significantly revised by Stith Thompson and Hans-Jörg Uther.