The Takkanot Shum (Hebrew: תקנות שו"ם), or Enactments of SHU"M, were a set of decrees formulated and agreed upon over a period of decades by the leaders of three of the central cities of Medieval Rhineland Jewry: Speyer, Worms, and Mainz. The initials of the Hebrew names for these cities, Shpira, Vermayza, and Magentza form the initials SHUM. While these regulations were intended to address the problems of that time, they had an effect on European Jewry that lasted centuries.[1]