  The dependence of the semileptonic kaon decay form factors on the 4-momentum
transfer to the lepton pair causes certain changes in the differential decay
rates and, hence, it should affect the conventional atmospheric neutrino flux
and neutrino flavour ratio. As a case in point, we included these rates into
the calculation of the atmospheric neutrino flux at energies 1 to 100 TeV.
  The calculated neutrino spectra are between the earlier predictions while the
neutrino flavor ratio, R, is somewhat affected by the kaon form factors. The R
proves to be very sensitive to the contribution of neutrinos from decay of
charmed particles, providing an additional method to test the charm production
models in future experiments with large-volume neutrino telescopes.
