  Supersymmetry is one of the best motivated new physics scenarios. To build a
realistic supersymmetric standard model, however, a companion symmetry is
necessary to address various issues. While R-parity is a popular candidate that
can address the proton and dark matter issues simultaneously, it is not the
only option for such a property. We review how a TeV scale U(1)' gauge symmetry
can replace the R-parity. Discrete symmetries of the U(1)' can make the model
still viable and attractive with distinguishable phenomenology. For instance,
with a residual discrete symmetry of the U(1)', Z6 = B3 x U2, the proton can be
protected by the baryon triality (B3) and a hidden sector dark matter candidate
can be protected by the U-parity (U2).
