  Bilinear R-parity violation is a simple extension of the MSSM allowing for
Majorana neutrino masses. One of the three neutrinos picks up mass by mixing
with the neutralinos of the MSSM, while the other two neutrinos gain mass from
1-loop corrections. Once 1-loop corrections are carefully taken into account
the model is able to explain solar and atmospheric neutrino data for specific
though simple choices of the R-parity violating parameters.
