Order issued by the Council of Vienna [Austria]: “Order issued by the Council of Vienna [Austria]: Canon 15- Since the Jews have become so arrogant […], we mandate that Jews have to be distinguished in their clothing from Christians and as a consequence have to resume wearing the horned hat they were accustomed to wear in these areas but stopped doing it because of their boldness.”
Scherer, Johann, Die rechtsverhaltnisse der Juden in den deutsch-osterreichischen landern, 1844, (The legal position of the Jews in the German-Austrian countries: With A Preface About The Principles: The Jewish legislation in Europe during the Middle Ages) page 332, Accessed online; Translated by Franziska Wagener 3/2/2016