  We report on empirical parameterizations of longitudinal and transverse
nuclear excitation electromagnetic form factors in ${\rm ^{12}C}$ and ${\rm
^{16}O}$. We extract the contribution of nuclear excitations to the Normalized
Inelastic Coulomb Sum Rule (\csr) as a function of momentum transfer $\bf q$
and find that it is significant (0.29$\pm$0.030 at $\bf q$= 0.22 GeV). The
total contributions of nuclear excitations to $S_L({\bf q})$ in ${\rm ^{12}C}$
and ${\rm ^{16}O}$ are found to be equal within the uncertainties. Since the
cross sections for nuclear excitations are significant, the radiative tails
from nuclear excitations should be included in precise calculations of
radiative corrections to quasielastic electron scattering at low $\bf q$ and
deep-inelastic electron scattering at large energy transfers $\nu$. The
parameterizations also serve as a benchmark in testing theoretical modeling of
cross sections for excitation of nuclear states in electron and neutrino
interactions on nuclear targets at low energies.
