  We analyze the properties of the soliton solutions of a class of models
describing one-dimensional BEC with spin F. We describe the minimal sets of
scattering data which determine uniquely both the corresponding potential of
the Lax operator and its scattering matrix. Next we give several reductions of
these MNLS, derive their N-soliton solutions and analyze the soliton
interactions. Finally we prove an important theorem proving that if the initial
conditions satisfy the reduction then one gets a solution of the reduced MNLS.
