The disordered flat phase of a crystal surface - critical and dynamic   properties
  We analyze a restricted SOS model on a square lattice with nearest and next-nearest neighbor interactions, using Monte Carlo techniques. In particular, the critical exponents at the preroughening transition between the flat and disordered flat (DOF) phases are confirmed to be non-universal. Moreover, in the DOF phase, the equilibration of various profiles imprinted on the crystal surface is simulated, applying evaporation kinetics and surface diffusion. Similarities to and deviations from related findings in the flat and rough phases are discussed. 
J. Klaers, W. Selke