2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/198435We explain why it is possible to formulate a wide variety of high energy (small-x) photon-proton processes in terms of a universal dipole cross section and compare and contrast various parameterizations of this function that exist in the literature.6 pages, latex, 2 figures. Contribution to Durham Collider Workshop (Sept 99) proceedingsHigh Energy Physics - Phenomenologytext