  Recent studies have shown that searches in the mono-photon and missing energy
final state can be used to discover dark matter candidates at the ILC. While an
excess in this final state over the Standard Model background would indicate
the existence of a dark sector, no detailed information about the internal
structure of this sector can be inferred. Here, we demonstrate how just a few
observables can discriminate between various realizations of dark sectors,
including e.g. the spin of mediators.
