  R-parity can be violated through either bilinear and/or trilinear terms in
the superpotential. The decay properties of sneutrinos can be used to obtain
information about the relative importance of these couplings provided
sneutrinos are the lightest supersymmetric particles. We show that in some
specific scenarios it is even possible to decide whether bilinear or trilinear
terms give the dominant contribution to the neutrino mass matrix.
