18Fxx Categories and geometry

18F05  Local categories and functors
18F10  Grothendieck topologies, See also {14F20}
18F15  Abstract manifolds and fiber bundles, See also {55Rxx,
               57Pxx}
18F20  Presheaves and sheaves, See also {14F05, 32C35, 32L10,
               54B40, 55N30}
18F25  Algebraic $K$-theory and $L$-theory, See also {11Exx,
               11R70, 11S70, 12-XX, 13D15, 14Cxx, 16E20, 19-XX, 
               46L80, 57R65, 57R67}
18F30  Grothendieck groups, See also {13D15, 16E20, 19Axx}
18F99  None of the above but in this section