  Energy conservation in radiating processes requires, at the classical level,
to take into account damping forces on the sources. These forces can be
represented in terms of asymptotic data and lead to charges defined as
integrals over the asymptotic boundary. For scattering processes these charges,
in case of zero radiated energy, are conserved and encode the information about
the sub-leading soft theorems and matching conditions. The QED version of the
self forces is associated with the dependence of the differential cross section
on the infrared resolution scale.
