A reincarnation of R-parity
  In supersymmetric theories, R-parity is defined in a way such that it does not commute with the space-time symmetries. We show that, in general sypersymmetric models, one can define a discrete symmetry which commutes with all space-time and gauge symmetries, and whose phenomenological implications are equivalent to those of R-parity. 
Palash B. Pal (Saha Institute, Calcutta)