The findings of Ghamlouch et al. [Phys. Rev. B 54, 9070 (1996)] on the jump in the thermoelectric power of high-T-c superconductors below the critical temperature in the presence of large magnetic fields are discussed. The complicated interplay between the vortex lattice thermodynamic transitions and the transport property percolation transitions raises questions on their similarities, differences, and relationships with respect to the (B,T) phase diagram features and the classical Kosterlitz-Thouless transition. A few comments pertain to the experimental details and others on the relevant role of thermomagnetic transport properties. [S0163-1829(99)04102-8].