Lateran Council of 1215

"… we decree that such Jews and Saracens [Muslims] of both sexes in every Chris-tian province and at all times shall be marked off in the eyes of the public from other peoples through the character of their dress. … Moreover, during the last three days before Easter and especially on Good Friday, they shall not go forth in public at all, for the reason that some of them on these very days, as we hear, do not blush to go forth better dressed and are not afraid to mock the Christians who maintain the memory of the most holy Passion by wearing signs of mourning." 

Canon 68. Jews appearing in public