  Different scenarios of the fluctuation-induced disordering of the striped
phase which is formed at low temperatures in the triangular-lattice Ising model
with the antiferromagnetic interaction of nearest and next-to-nearest neighbors
are analyzed and compared. The dominant mechanism of the disordering is related
to the formation of a network of domain walls, which is characterized by an
extensive number of zero modes and has to appear via the first-order phase
transition. In principle, this first-order transition can be preceded by a
continuous one, related to the spontaneous formation of double domain walls and
a partial restoration of the broken symmetry, but the realization of such a
scenario requires the fulfillment of rather special relations between the
coupling constants.
