nodal displacement / force boundary conditions -- these need not be entered for every node; if unspecified it is assumed zero. If no b.c.'s are to be given, just enter the two ending zeros.
example:

(a)   (b)         (c)
23     0      -0.1    0.0

(a) node # -- global index number of node
(b) gen order -- used to specify a range of nodes; generally just leave it 0 unless doing something special.
(c) displacement values -- there are ndof numbers; these give the 1-, 2- or 3-dimensional displacement to apply to this node. These are interpreted as specified displacements as long as the corresponding degree of freedom is fixed (0); if the d.o.f. is free (1), then these entries are interpreted as nodal forces.

End nodal boundary condition block with two zeros.