Abstract: Marking sleeve for marking wires or pipes in the form of an annular or sleeve-shaped body manufactured in one piece and made of an elastic material. The marking sleeve is intended to bear one or more marking symbols and includes a yoke-shaped outer part with two outer legs which serve as side walls. At their lower ends, these legs merge with an inner yoke-shaped outer part, which extends up between the legs, with two inner legs and a web portion joining the upper ends of these. This web portion, together with the surrounding yoke-shaped outer part, delimits a tunnel-shaped passage for a wire which is to be marked. The outer surface of each of the outer legs is made with at least one longitudinal groove, and the mutually facing surfaces of each of the inner legs are made with at least one longitudinal groove.