Abstract: This invention pertains to a system of counterfoil binding, fit in particular to classify documents in the form of loose sheets; it includes a number of thin superposed strips (2), which are bound together by any convenient means and covered, on either side, with an adhesive layer (1), characterized by the fact that the whole of the adhesive surface (1) is covered with a coating (3) in which is provided at least a line (4) of least resistance making it possible to partially remove the film (3a) as to substitute for it at least part of the loose sheet to be classified (7); in this way the sheet lies in the prolongation of the detached part (3b) of the film.