  It is shown how one can apply the classification of the holonomy algebras of
Lorentzian manifolds to solve some problems. In particular, a new proof to the
classification of Lorentzian manifolds with recurrent curvature tensor is
given; the classification of two-symmetric Lorentzian manifolds is explained;
conformally recurrent Lorentzian manifolds are classified; recurrent symmetric
bilinear forms on Lorentzian manifolds are described.
