The title reflects only imperfectly the importance of this study, which, far from being limited to the north of France, embraces the Ashkenaze area (Northern France and Germany, but without addressing England) and embraces examples from the sepharade world (Provence, Iberian Peninsula) and Italy, or even from the Eastern Mediterranean (Genizah du Cairo in particular). Despite the high estimate of witnesses kept in current libraries (tens of thousands of manuscripts or fragments d...