16D99 None of the above, but in this section

16Exx Homological methods {For commutative rings, see <a href="#code:13Dxx">13Dxx</a>; for general categories, see <a href="#code:18Gxx">18Gxx</a>}

16E20 Grothendieck groups, $K$-theory, etc. [See also <a href="#code:18F30">18F30</a>, <a href="#code:19Axx">19Axx</a>, <a href="#code:19D50">19D50</a>]

16E30 Homological functors on modules (Tor, Ext, etc.)

16E40 (Co)homology of rings and algebras (e.g. Hochschild, cyclic, dihedral, etc.)

16E45 Differential graded algebras and applications

16E50 von Neumann regular rings and generalizations

16E60 Semihereditary and hereditary rings, free ideal rings, Sylvester rings, etc.

16E65 Homological conditions on rings (generalizations of regular, Gorenstein, Cohen-Macaulay rings, etc.)

16E99 None of the above, but in this section

16Gxx Representation theory of rings and algebras

16G20 Representations of quivers and partially ordered sets

16G30 Representations of orders, lattices, algebras over commutative rings [See also <a href="#code:16Hxx">16Hxx</a>]

16G60 Representation type (finite, tame, wild, etc.)

16G70 Auslander-Reiten sequences (almost split sequences) and Auslander-Reiten quivers

16G99 None of the above, but in this section

16Hxx Algebras and orders {For arithmetic aspects, see <a href="#code:11R52">11R52</a>, <a href="#code:11R54">11R54</a>, <a href="#code:11S45">11S45</a>; for representation theory, see <a href="#code:16G30">16G30</a>}

16H05 Separable algebras (e.g., quaternion algebras, Azumaya algebras, etc.)

16H99 None of the above, but in this section

16Kxx Division rings and semisimple Artin rings [See also <a href="#code:12E15">12E15</a>, <a href="#code:15A30">15A30</a>]

16K20 Finite-dimensional {For crossed products, see <a href="#code:16S35">16S35</a>}

16K50 Brauer groups [See also <a href="#code:12G05">12G05</a>, <a href="#code:14F22">14F22</a>]

16K99 None of the above, but in this section

16L30 Noncommutative local and semilocal rings, perfect rings

16L60 Quasi-Frobenius rings [See also <a href="#code:16D50">16D50</a>]