Joint Academic Coding System
The Joint Academic Coding System (JACS) system was used by the Higher Education Statistics Agency (HESA) and the Universities and Colleges Admissions Service (UCAS) in the United Kingdom to classify academic subjects. It was replaced by the Higher Education Classification of Subjects (HECoS) and the Common Aggregation Hierarchy (CAH) for the 2019/20 academic year.
Source: Wikipedia — Joint Academic Coding System (CC BY-SA 4.0)