This record causes remeshing.
Nodes are replaced either such that the mesh becomes more regular (geometric remeshing) or such that the mesh becomes more dense in areas of residues (residue remeshing).
By example, the geometric remeshing can be used after local mesh refinement (control_mesh_refine_locally). And by example, the residue remeshing can be used so that nodes follow wave propagation phenomena.
The remeshing is done with number_of_passes sweeps through the mesh, for each iteration (see control_timestep_iteration) of a time increment (see control_timestep). Typically, number_of_passes is 2 or 3.
If derivatives is initialized, TOCHNOG adjusts the unknowns for changing nodal positions (new unknown = old unknown + gradient * node replacement); this is only strictly required for history dependent or transient calculations.
See also control_mesh_remesh_factor and node_boundary.