  We generalize results of lattice QCD to determine the spin-dependent
symmetries and factorization properties of meson production in OZI allowed
processes. This explains some conjectures previously made in the literature
about axial meson decays and gives predictions for exclusive decays of vector
charmonia, including ways of establishing the structure of Y(4260) and Y(4325)
from their S-wave decays. Factorization gives a selection rule which forbids
$e^+e^- \to D^* D_2$ near threshold with the tensor meson in helicity 2. The
relations among amplitudes for double charmonia production $\e^+e^-\to
\psi\chi_{0,1,2}$ are expected to differ from the analagous relations among
light flavour production such as $\e^+e^-\to \omega f_{0,1,2}$.
