  The scalar potential of the Minimal Supersymmetric Standard Model (MSSM) is
nearly flat along many directions in field space. We provide a catalog of the
flat directions of the renormalizable and supersymmetry-preserving part of the
scalar potential of the MSSM, using the correspondence between flat directions
and gauge-invariant polynomials of chiral superfields. We then study how these
flat directions are lifted by non-renormalizable terms in the superpotential,
with special attention given to the subtleties associated with the family index
structure. Several flat directions are lifted only by supersymmetry-breaking
effects and by supersymmetric terms in the scalar potential of surprisingly
high dimensionality.
