06Axx Ordered sets
- 06A05 Total order
- 06A06 Partial order, general (1)
- 06A07 Combinatorics of partially ordered sets
- 06A11 Algebraic aspects of posets
- 06A12 Semilattices [See also 20M10; for topological semilattices see 22A26]
- 06A15 Galois correspondences, closure operators
- 06A75 Generalizations of ordered sets
- 06A99 None of the above, but in this section