Mathematics Subject Classification

https://en.wikipedia.org/wiki/Mathematics_Subject_Classification

Structure

• MSC is a 3 level deep hierarchical scheme

• classification code can have 2, 3 or 5 digits, depending on specificity

Levels

1. The first level code (FLC) is a 2-digit number.

2. The second level code (SLC) is a letter or a dash.

3. The third level code (TLC) is 2-digit number.

For example

• 53-xx: Differential geometry (or just 53)

• 53Axx: Classical differential geometry (or just 53A)

• 53A45: Vector and tensor analysis

First level

• 64 mathematical disciplines are labeled with a unique 2-digit code.

• there are top-level categories for typical areas and for the overlaps

• mathematical physics is well represented taking categories 70-86

• valid MSC classification codes must have at least FLC.

Second level

• SLC are a letter or a dash.

• 2nd-level is for specific fields of the 1st-level disciplines.

• SLC vary across the disciplines. e.g.:

  • 53 : Differential Geometry's FLC

  • 53A: Classical Differential Geometry

  • 53B: Local Differential Geometry

  • 53C: Global Differential Geometry

  • 53D: Symplectic Geometry And Contact Geometry

Second level's special subsection

• dash marks the special subsection, always with the same contents:

  • FLC-00: General reference works

  • FLC-01: Instructional exposition

  • FLC-02: Research exposition

  • FLC-03: Historical

  • FLC-04: Explicit machine computation and programs

  • FLC-06: Proceedings, conferences, collections, etc.

• it is not valid to use trailing dash, e.g. "53-", just use 53

Third level

• 3rd-level codes are the most specific subjects

• TLC ending in 99 is "none-of-the-above", "other" placement for every category

Using the scheme

The AMS recommends that papers submitted to its journals for publication have one primary classification and one or more optional secondary classifications. A typical MSC subject class line on a research paper looks like: MSC Primary 03C90; Secondary 03-02;