[en] A unified semiclassical theory of analysing powers of all ranks for polarised heavy-ion elastic scattering from a spin-zero target at energies above the Coulomb barrier is presented. Illustration is provided for by specialising to the two interactions, spin-orbit and tensor. The present approach recovers the phenomenological result, obtained by taking the difference of the nuclear overlap between unpolarised and aligned projectiles (shape-effect model), which successfully explained the structureless pattern of rank-2 observables for aligned ⁷Li+⁵⁸Ni at Esub(lab)proportional20 MeV. Deviations observed for ⁷Li+¹²C (oscillations) are interpreted as due to interference between diffraction (positive-angle) and negative-angle scattering terms. (orig.)