  A brief and incomplete review of known integrable and
(quasi)-exactly-solvable quantum models with rational (meromorphic in Cartesian
coordinates) potentials is given. All of them are characterized by (i) a
discrete symmetry of the Hamiltonian, (ii) a number of polynomial
eigenfunctions, (iii) a factorization property for eigenfunctions, and admit
(iv) the separation of the radial coordinate and, hence, the existence of the
2nd order integral, (v) an algebraic form in invariants of a discrete symmetry
group (in space of orbits).
