[en] Compatible with all available neutral current data, including parity violation recently observed at SLAC, the symmetry structure SU(2)sub(L) X SU(2)sub(R) X U(1)sub(L) X U(1)sub(R) arising naturally within quark-lepton unifying symmetries of the form [SU(4)]⁴, can lead to new complexions in the parity-conserving part of the neutral current interaction compared with SU(2)sub(L) X U(1); simultaneously it could provide a weak gauge boson lighter than the Z⁰ of SU(2)sub(L) X U(1). These new complexions can easily be detected at PETRA and PEP and perhaps also at SPEAR: these, if present, would provide us with further guidance towards a complete unification. The implications of the SLAC findings on the basic hypothesis of left-right symmetry are clarified. (Auth.)