[en] This is the third paper in a series of three papers which considers the physical properties of torsions in Riemann-Cartan space-times U₄. Paper three briefly considers some of the simpler generalizations of the ECSK theory together with their covering theories, and a simple classification scheme for torsions is introduced that depends in part on the Weyl conformal curvature tensor. Moreover, further consideration is given to the possible physical role of the third-order ''spin'' tensor of Lanczos and to observations that could be made with spinning and nonspinning test particles. In particular, we consider the possible importance of the Lanczos V₄ variational identity with Riemannian constraints in connection with speculations concerning the question of their microphysical significance