  A method for deriving the asymptotic behaviour of any physical field is
presented. This leads to a geometrically meaningful derivation of the peeling
properties for arbitrary values of the cosmological constant. Application to
the outstanding case of the physical Weyl tensor provides the explicit form of
all terms that determine its asymptotic behaviour along arbitrary lightlike
geodesics. The results follow under the assumption of a conformal completion
\`a la Penrose. The only freedom available is the choice of a null vector at
the conformal boundary of the space-time (which determines the lightlike
geodesic arriving there).
