アメリカの数学会だと

Algebraic Geometry; Algebraic Topology; Analysis of PDEs; Category Theory;
Classical Analysis and ODEs; Combinatorics; Commutative Algebra;
Complex Variables; Differential Geometry; Dynamical Systems; Functional Analysis;
General Mathematics; General Topology; Geometric Topology; Group Theory;
History and Overview; Information Theory; K-Theory and Homology; Logic;
Mathematical Physics; Metric Geometry; Number Theory; Numerical Analysis;
Operator Algebras; Optimization and Control; Probability; Quantum Algebra;
Representation Theory; Rings and Algebras; Spectral Theory; Statistics Theory;
Symplectic Geometry

って分類になってるようだけど
General Mathematics
History and Overview
Metric Geometry
辺りがどんなことやるのかわからない