Jews being beaten, from an English manuscript.
Medieval Catholic Europe
In the Medieval, largely Catholic Europe, in some periods Jews and Muslims were required to wear distinguishable clothing. These measures were not seen as being inconsistent with Sicut Judaeis. Though 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:
In some provinces a difference in dress distinguishes the Jews or Saracens from the Christians, but in certain others such a confusion has grown up that they cannot be distinguished by any difference. Thus it happens at times that through error Christians have relations with the women of Jews or Saracens, and Jews and Saracens with Christian women. Therefore, that they may not, under pretext of error of this sort, excuse themselves in the future for the excesses of such prohibited intercourse, we decree that such Jews and Saracens of both sexes in every Christian province and at all times shall be marked off in the eyes of the public from other peoples through the character of their dress. Particularly, since it may be read in the writings of Moses [Numbers 15:37-41], that this very law has been enjoined upon them.
Innocent III had in 1199 confirmed Sicut Judaeis, which was also confirmed by Pope Honorius III in 1216. In 1219, Honorius III issues a dispensation to the Jews ofCastile, the largest Jewish population in Europe. Spanish Jews normally wore turbans in any case, which presumably met the requirement to be distinctive.Elsewhere, local laws were introduced to bring the canon into effect. The identifying mark varied from one country to another, and from period to period.
In 1227, the Synod of Narbonne, in canon 3, ruled:
That Jews may be distinguished from others, we decree and emphatically command that in the center of the breast (of their garments) they shall wear an oval badge, the measure of one finger in width and one half a palm in height...
However, these ecclesiastic pronouncements required legal sanctions of a temporal authority. In 1228, James I of Aragon ordered Jews of Aragon to wear the badge;and in 1265, the Siete Partidas, a legal code enacted in Castile by Alfonso X but not implemented until many years later, included a requirement for Jews to wear distinguishing marks. On 19 June 1269, Louis IX of France imposed a fine of ten livres (one livre was equivalent to a pound of silver) on Jews found in public without a badge (Latin: rota, "wheel", French: rouelle or roue). The enforcement of wearing the badge is repeated by local councils, with varying degrees of fines, at Arles1234 and 1260, Béziers 1246, Albi 1254, Nîmes 1284 and 1365, Avignon 1326 and 1337, Rodez 1336, and Vanves 1368. The "rota" looked like a ring of white or yellow. The shape and color of the patch also varied, although the color was usually white or yellow. Married women were often required to wear two bands of blue on their veil or head-scarf.
Each Jew, after he is seven years old, shall wear a distinguishing mark on his outer garment, that is to say, in the form of two Tables joined, of yellow felt of the length of six inches and of the breadth of three inches.
In German-speaking Europe, a requirement for a badge was less common than the Judenhut or Pileum cornutum (a cone-shaped head dress, common in medieval illustrations of Jews). In 1267, in a special session, the Vienna city council required Jews to wear a Judenhut; the badge does not seem to have been worn in Austria. There is a reference to a dispensation from the badge in Erfurt on 16 October 1294, the earliest reference to the badge in Germany.
As with all sumptuary laws, enforcement of the rules was variable; in Marseilles the magistrates ignored accusations of breaches, and in some places individuals or communities could buy exemption. Cathars who were considered "first time offenders" by the Catholic Church and the Inquisition were also forced to wear yellow badges, albeit in the form of crosses, about their person.
Jews (identifiable byrouelle) being burned at stake. From medieval manuscript.
Jewish ring from a Hebrew Passover manuscript, German 15th century.
The yellow badge is different from the Jewish hat (or "Judenhut"), a cone-shaped hat, which is seen in many illustrations from before this date, and remained the key distinguishing mark of Jewish dress in the Middle Ages. From the 16th century, the use of the Judenhut declined, but the badge tended to outlast it, surviving into the 18th century in places.
Yellow badge made mandatory by the Nazis in France
After the German invasion of Poland in 1939 there were initially different local decrees requiring Jews to wear a distinctive sign, during the General Government. The sign was a white armband with a blue Star of David on it, in the Warthegau a yellow badge in the form of a Star of David on the left side of the breast and on the back. The requirement to wear the Star of David with the word Jude(German for Jew) inscribed in faux Hebrew letters was then extended to all Jews over the age of six in the Reich and the Protectorate of Bohemia and Moravia (by a decree issued on September 19, 1941, signed by Reinhard Heydrich) and was gradually introduced in other German-occupied areas, where local words were used (e.g., Juif in French, Jood in Dutch).
One observer reported that the star increased German non-Nazi sympathy for Jews as the impoverished citizens who wore them were, contrary to Nazi propaganda, obviously not the cause of German failure in the east. In Czechoslovakia, the government had to ban hat tipping toward Jews and other courtesies that became popular as protests against the German occupation. A whispering campaign that claimed that the action was in response to the United States government requiring German Americans to wear swastikas was unsuccessful.
Muslim countries recently
During the rule of the Islamist Taliban regime in Afghanistan, the Hindu minority in the Islamic Emirate of Afghanistan were forced to wear yellow badges in public to identify themselves as such as part of the Taliban's plan to segregate "un-Islamic" and "idolatrous" communities from Islamic ones. The decree was condemned by the Government of the United States as a gross violation of religious freedom, with congressmen and several lawmakers wearing yellow badges on the floor of the Senate during the debate as a demonstration of their solidarity with the Hindu minority in Afghanistan, and the chairman of the US Anti-Defamation League,Abraham Foxman, compared the decree to the earlier practice of the Nazi regime. Widespread protests against the Taliban regime broke out in Bhopal,India, and the Government of India condemned this decree as a violation of religious freedom.
Medieval and Early Modern Europe
Fourth Lateran Council headed by Pope Innocent III declares: "Jews and Saracens of both sexes in every Christian province and at all times shall be marked off in the eyes of the public from other peoples through the character of their dress." 
Synod of Narbonne rules: "That Jews may be distinguished from others, we decree and emphatically command that in the center of the breast (of their garments) they shall wear an oval badge, the measure of one finger in width and one half a palm in height." 
In a special session, the Vienna city council forces Jews to wear Pileum cornutum (a cone-shaped head dress, common in medieval illustrations of Jews); the badge does not seem to have been worn in Austria.
1269, June 19
France. (Saint) Louis IX of France orders all Jews found in public without a badge (French: rouelle or roue, Latin: rota) to be fined ten livres of silver. The enforcement of wearing the badge is repeated by local councils, with varying degrees of fines, at Arles 1234 and 1260, Béziers 1246, Albi 1254, Nîmes 1284 and 1365, Avignon 1326 and 1337, Rodez 1336, and Vanves 1368.
The Statute of Jewry in England, enacted by King Edward I, enforces the regulations. "Each Jew, after he is seven years old, shall wear a distinguishing mark on his outer garment, that is to say, in the form of two Tables joined, of yellow felt of the length of six inches and of the breadth of three inches." 
1294, October 16
1415, May 11
The Council of Ten of Venice allows the newly arrived famous physician and professor Jacob Mantino ben Samuel to wear the regular black doctors' cap instead of Jewish yellow hat for several months (subsequently made permanent), upon the recommendation of the French and English ambassadors, the papal legate, and other dignitaries numbered among his patients.
1935, 15 September
1938, August 17
Jewish Germans and stateless Jews with Austrian citizenship are required to adopt additional middle names (mostly Israel or Sarah, few other derogatory names considered "Jewish" were alternatively possible) to be used at any occasion such as signatures, visit cards, addresses, firms etc.
Jewish Germans had to turn in their passports to get them stamped in a black J. As Jewish Austrians had been denied German citizenship, their Austrian passports became void.
Jewish Germans and Austrians had to adopt special identity cards to be carried on them whenever away from home.
1939, September and October
A number of local German occupational commanders ordered Jewish Poles in their areas to wear an identifying mark under the threat of death. There were no consistent requirements as to its color and shape: it varies from a white armband to a yellow Star of David badge.
1939, 23 November
A popular legend portrays king Christian X of Denmark wearing the yellow badge on his daily morning horseback ride through the streets of Copenhagen, followed by non-Jewish Danes responding to their king's example, thus preventing the Germans from identifying Jewish citizens. Queen Margrethe II of Denmark has explained that the story was not true. No order requiring Jews to wear identifying marks was ever introduced in Denmark.
1941, June 4
Jewish Poles in German-occupied Soviet-annexed Poland, Jewish Lithuanians, Latvians and Estonians as well as Soviet Jews in German-occupied areas were obliged to wear white armbands or yellow badges.
1941, August 8
All Romanian Jews were ordered to wear the yellow badge.
1941, August 13
The yellow badge was the only standardised identifying mark in the German-occupied East; other signs were forbidden.
1941, September 1
Jewish Germans and Jews with citizenship of annexed states (Austrians, Czechs, Danzigers) from the age of six years were ordered to wear the yellow badge when in public.
1941, September 9
Slovakia ordered its Jews to wear yellow badges.
Romania started to force Jews in newly annexed territories, denied Romanian citizenship, to wear the yellow badge.
1942, March 13
1942, April 29
Jewish Dutch people forced to wear the yellow badge.
1942, June 3
Jewish Belgians forced to wear the yellow badge.
1942, June 7
Jews in occupied France were ordered to wear a yellow star, but the Vichy Regime refused to comply with that.
With the German annexation of Luxembourg, the yellow badge was introduced there.
Under German pressure, Bulgaria ordered its Jewish citizens to wear small yellow buttons, but contravention was not prosecuted.
With the occupation of the French Zone libre Jews there were also forced to wear the yellow badge.
1944, March 31
After the occupation of Hungary, the German occupants ordered Jewish Hungarians and Jews with defunct other citizenships (Czechoslovakian, Romanian, Yugoslavian) in Hungarian-annexed areas to wear the yellow badge.