  Estimates of QED and dispersion effects on the cross section for elastic
electron scattering from a 12C nucleus are provided for collision energies in
the range of 120-450 MeV. While in general such corrections are smoothly
varying with energy or scattering angle, they show structures in the vicinity
of diffraction minima which are very sensitive to details of the theoretical
models. This casts doubt on the assertion that the discrepancy between QED
background-corrected experimental data and theory in these minima originates
solely from dispersion.
