The Jewish sign was generally a yellow ring which the Jews had to wear on their clothing. This was created by the Catholic church in the Middle Ages in order to identify the Jews and distinguish them from Christians. The regulations were first issued at the IV Lateran Council in 1215, but were not implemented in Germany for a long time. In the period before the creation of the Judengasse in the 13th and 14th centuries there was no difference in the clothing worn by the Jews and their Christian neighbours. In 1451, faced by the demand of the famous cardinal legate Nicolaus von Cues, the Frankfurt city council enforced a code by 1460 under which Frankfurt Jews also had to wear a special sign on their clothing.
After the creation of the Judengasse the Jews had to wear the Jewish sign, a yellow ring, on their clothing. However, this regulation seems to have been ignored for a long period, since there are frequent complaints of the failure to observe it. The Jews managed to weaken the code at times: for example, at the Regensburg parliament in 1546 the emperor Charles V released the Jews from the need to wear the sign when they were traveling on country roads. However, the Jewish sign was retained and was embodied in the residence code of 1616. It was not until 1728 that the Vienna imperial council finally abolished the special Frankfurt sign for Jews, over the protest of the Frankfurt city council. The Vienna council justified this with the argument that Frankfurt's citizens had not suffered even though the code had not been observed for years. Even so, the Jews continued to be distinguished by their dress, a characteristic Jewish style which marked them as a separate group.