57Nxx Topological manifolds
 57N05 Topology of E2, 2manifolds
 57N10 Topology of general 3manifolds [See also 57Mxx]
 57N12 Topology of E3 and S3 [See also 57M40]
 57N13 Topology of E4, 4manifolds [See also 14Jxx, 32Jxx]
 57N15 Topology of En, nmanifolds (4 < n <1)
 57N16 Geometric structures on manifolds [See also 57M50]
 57N17 Topology of topological vector spaces
 57N20 Topology of infinitedimensional manifolds [See also 58Bxx]

57N25 Shapes [See also 54C56, 55P55, 55Q07]
(1)
 57N30 Engulfing
 57N35 Embeddings and immersions
 57N37 Isotopy and pseudoisotopy
 57N40 Neighborhoods of submanifolds
 57N45 Flatness and tameness
 57N50 Sn1 ⊂ En, Schoenflies problem
 57N55 Microbundles and block bundles [See also 55R60, 57Q50]
 57N60 Cellularity
 57N65 Algebraic topology of manifolds
 57N70 Cobordism and concordance
 57N75 General position and transversality
 57N80 Stratifications
 57N99 None of the above, but in this section