  The BaBar analysis which favours $2^{-+}$ quantum numbers for the X(3872)
implies that it may be none other than the 1D2 charmonia state. In that case
the isospin breaking in closed flavour modes may be the result of re-scattering
from open flavour. However, the observed production cross section in
proton-antiproton collisions is much larger than expectations, while the mass
of the state, compared to the predictions of a string model, is too high. The
1D2 assignment would imply a 3D2 partner nearby in mass, which may be the
X(3875). In the tetraquark interpretation the $2^{-+}$ assignment implies a
rich spectrum of partner states, although the X(3872) may be among the few
which are narrow enough to be observable. This talk is based in part on "The
2-+ assignment for the X(3872)" by T. J. Burns, F. Piccinini, A. D. Polosa & C.
Sabelli (Phys. Rev. D 82, 074003 (2010); arXiv:1008.0018 [hep-ph]).
