  After a brief account of the algebraic version of renormalization group
developed by Buchholz and Verch, and of the main results of the Doplicher-Haag-
Roberts theory of superselection sectors, we introduce the notion of asymptotic
charge transfer chain, through which it is possible to reconstruct the scaling
limit theory's superselection structure entirely in terms of underlying
theory's observables. Furthermore, these objects allow the formulation of a
natural notion of preservation of a charge in the scaling limit, so that one
gets an intrinsic definition of confined charges, as those charges of the
scaling limit which do not come from preserved charges of the underlying
theory. This is an expository account of the results. Proofs will be published
elsewhere.
