Yellow badge
The yellow badge (or yellow patch), also referred to as a Jewish badge (German: Judenstern, lit. Jews' star), was a cloth patch that Jews were ordered to sew on their outer garments to mark them as Jews in public at certain times in certain countries. Intended or not, it served as a badge of shame.
Usage
Islamic world
The practice of wearing special markings in order to distinguish Jews and other non-Muslims (Dhimmis) in Muslim-dominated countries seems to have been introduced by Umayyad Caliph Umar II in early 8th century.The practice was reissued and reinforced by Caliph Al-Mutawakkil (847–61), subsequently remaining in force for centuries. A genizah document from 1121 gives the following description of decrees issued in Baghdad:
Medieval Catholic Europe
In largely Catholic Medieval Europe Jews and Muslims were required to wear distinguishable clothing in some periods. These measures were not seen as being inconsistent with Sicut Judaeis. Although not the first ecclesiastic requirement for non-Christians to wear distinguishable clothing, the Fourth Council of the Lateran headed by Pope Innocent III ruled in 1215 that Jews and Muslims must wear distinguishable dress (Latin habitus). Canon 68 reads, in part: