05XX 


Combinatorics {For finite fields, see 11Txx} 

05Bxx 

Designs and configurations {For applications of design theory, see 94C30} 


05B05 
Block designs [See also 51E05, 62K10] 


05B07 
Triple systems 


05B10 
Difference sets (numbertheoretic, grouptheoretic, etc.) [See also 11B13] 


05B15 
Orthogonal arrays, Latin squares, Room squares 


05B20 
Matrices (incidence, Hadamard, etc.) 


05B25 
Finite geometries [See also 51D20, 51Exx] 


05B30 
Other designs, configurations [See also 51E30] 


05B35 
Matroids, geometric lattices [See also 52B40, 90C27] 


05B40 
Packing and covering [See also 11H31, 52C15, 52C17] 


05B45 
Tessellation and tiling problems [See also 52C20, 52C22] 


05B50 
Polyominoes 


05B99 
None of the above, but in this section 