  We contribute to the subject of the physical interpretation of exact
solutions by characterizing them through a systematic study in terms of
unambiguous physical concepts coming from systems in linearized gravity. We use
the physical meaning of the leading order behavior of the Weyl spinor
components $\Psi_0^0$, $\Psi_1^0$ and $\Psi_2^0$ and of the Maxwell spinor
components $\phi_0^0$ and $\phi_1^0$ and integrate from future null infinity
inwards the exact field equations. In this way it is assigned an unambiguous
physical meaning to exact solutions. We indicate a method to generalize the
procedure to radiating spacetimes.
