Edge-coloring of multigraphs: Recoloring technique

New upper and lower bounds for the chromatic index of a finite muitigraph are obtained. A complete description is given of multigraphs satisfying χ′ > 1/8(9ρ + 6) where χ′ and ρ denote the chromatic index and the maximum vertex degree of a multigraph. Some new and old conjectures are discussed.