(Moreau's Roman Diary, January 1, 1851)
Finally on December 22nd, His Holiness, received Reverend Father for the 3rd time . . . . "I told Msgr. De Merode, "Said the Holy Father to Moreau, 'That I would take away your rabat. I want it.' In fact, the Holy Father did take it away, adding that he would send Father Moreau a little collar after the style of that worn by St. Vincent de Paul and that he would like to see it worn by him and his religious, even by the Brothers." Footnote: The rabat was the type of Clerical collar then used by the secular clergy of France; its distinguishing character was the two white flaps which protruded over the collar of the soutene. The Holy Father wished Father Moreau and all his religious to use henceforth the simple white collar without the flaps; this style was called the 'Roman' because it was worn generally by the clergy of Rome.
See also under "Clothing" (for Brothers)