[Possible/Probable] “Constitutions of Stephen Langton” Issued by Archbishop Stephen Langton of Canterbury [England] [Unconfirmed]
Commentary from other sources:
1) “[A]rchbishop of canterbury Stephen Langton orders english language jews [to] wear white band[s] 2 fingers broad, 4 fingers long.”
Cyrus Adler, Joseph Jacobs: “BADGE;” jewishencyclopedia.com
2) “This decree prohibited Christians from having any communication with Jews, or selling them provisions, upon pain of excommunication.”
The Jewish Herald and Record of Christian Effort for the Spiritual Good of God’s Ancient People: (London, 1852) p. 13