  We discuss semi-inclusive Deep Inelastic Scattering (DIS) in the z -> 1
limit, in particular the relationship between fracture functions, generalised
cut vertices and Green functions of the composite operators arising in the OPE.
The implications, in the spin-polarised case, for testing whether the "proton
spin" effect is target-independent are explored. Explicit calculations in
(phi^3)_6 theory are presented which are consistent with our observations.
