  We compute three and four point functions of the non-BPS scattering
amplitudes, including a closed string Ramond-Ramond, gauge/scalar and tachyon
in type IIA (IIB) superstring theories. We then discover a unique expansion for
tachyon amplitudes in both non-BPS and D-brane anti D-brane formalisms. Based
on remarks on Chan-Paton factors and arXiv:1304.3711, we propose selection
rules for all non-BPS scattering amplitudes of type II superstring theory.
These selection rules, rule out various non-BPS higher point correlation
functions of the string theory.
