13-00 General reference works (handbooks, dictionaries, bibliographies, etc.)
13-01 Instructional exposition (textbooks, tutorial papers, etc.)
13-02 Research exposition (monographs, survey articles)
13-03 Historical (must also be assigned at least one classification number from Section 01)
13-04 Explicit machine computation and programs (not the theory of computation or programming)
13-06 Proceedings, conferences, collections, etc.
13Axx General commutative ring theory
13Bxx Ring extensions and related topics
13Cxx Theory of modules and ideals
13Dxx Homological methods {For noncommutative rings, see 16Exx; for general categories, see 18Gxx}
13Exx Chain conditions, finiteness conditions
13Fxx Arithmetic rings and other special rings
13G05 Integral domains
13Hxx Local rings and semilocal rings
13Jxx Topological rings and modules [See also 16W60, 16W80]
13K05 Witt vectors and related rings
13L05 Applications of logic to commutative algebra [See also 03Cxx, 03Hxx]
13Mxx Finite commutative rings {For number-theoretic aspects, see 11Txx}
13Nxx Differential algebra [See also 12H05, 14F10]
13Pxx Computational aspects of commutative algebra [See also 68W30]