## 51Exx Finite geometry and special incidence structures

- 51E05 General block designs [See also 05B05]
- 51E10 Steiner systems
- 51E12 Generalized quadrangles, generalized polygons
- 51E14 Finite partial geometries (general), nets, partial spreads
- 51E15 Affine and projective planes (2)
- 51E20 Combinatorial structures in finite projective spaces [See also 05Bxx] (1)
- 51E21 Blocking sets, ovals, k-arcs
- 51E22 Linear codes and caps in Galois spaces [See also 94B05]
- 51E23 Spreads and packing problems
- 51E24 Buildings and the geometry of diagrams
- 51E25 Other finite nonlinear geometries
- 51E26 Other finite linear geometries
- 51E30 Other finite incidence structures [See also 05B30]
- 51E99 None of the above, but in this section