  We advocate for a simple multipole expansion of the polarization density
matrix. The resulting multipoles are used to construct bona fide
quasiprobability distributions that appear as a sum of successive moments of
the Stokes variables; the first one corresponding to the classical picture on
the Poincare sphere. We employ the particular case of the $Q$ function to
formulate a whole hierarchy of measures that properly assess higher-order
polarization correlations.
