51D05 Abstract (Maeda) geometries
51D10 Abstract geometries with exchange axiom
51D15 Abstract geometries with parallelism
51D20 Combinatorial geometries [See also 05B25, 05B35]
51D25 Lattices of subspaces [See also 05B35]
51D30 Continuous geometries and related topics [See also 06Cxx]
51D99 None of the above, but in this section