This is a brief description of how my mathematical blog posts will be categorized. Although the Mathematics Subject Classification (MSC) scheme is perhaps the most official, I will be employing the same description as used by the arxiv. This means that the possible areas are the following:

- Algebraic Geometry (math.AG)
- Algebraic Topology (math.AT)
- Analysis of PDEs (math.AP)
- Classical Analysis and ODEs (math.CA)
- Category Theory (math.CT)
- Combinatorics (math.CO)
- Commutative Algebra (math.AC)
- Complex Variables (math.CV)
- Differential Geometry (math.DG)
- Dynamical Systems (math.DS)
- Functional Analysis (math.FA)
- General Mathematics (math.GM)
- General Topology (math.GN)
- Geometric Topology (math.GT)
- Group Theory (math.GR)
- History and Overview (math.HO)
- Information Theory (math.IT)
- K-Theory and Homology (math.KT)
- Logic (math.LO)
- Mathematical Physics (math.MP)
- Metric Geometry (math.MG)
- Numerical Analysis (math.NA)
- Number Theory (math.NT)
- Operator Algebras (math.OA)
- Optimization and Control (math.OC)
- Probability (math.PR)
- Quantum Algebra (math.QA)
- Representation Theory (math.RT)
- Rings and Algebras (math.RA)
- Spectral Theory (math.SP)
- Statistics (math.ST)
- Symplectic Geometry (math.SG)

Of course, I almost certainly won’t refer to all of them, but I will use many. I will also use math.REC for recreational mathematics, which I do all the time.