  Flipping a symmetry often leads to a more fundamental symmetry and new
physics insight. Applying this principle to the standard model electroweak
symmetry, we obtain a novel gauge symmetry, which defines dark charge besides
electric charge, neutrino mass mechanism, and resultant dark parity as residual
flipped symmetry. The dark parity divides the model particles into two classes:
odd and even. The dark matter candidate transforms as a fermion or a scalar
singlet, having a mass below the electron mass, being stabilized by the dark
parity. Scenarios for consistent neutrino mass generation and dark matter relic
are proposed. The nature and further implication of the flipping approach are
determined.
