T. C. Noble, A Brief History of the Worshipful Company of Ironmongers…
“ By ordinance dated 1657 no person is to change the copy of his freedom, and by an order of Court made November 21, 1878, “no person who is free of any other Company can be admitted to the freedom of the Ironmongers’ Company, nor can he become free of another Company after being admitted to the freedom of this Company.” This order necessarily makes the Ironmongers a select body corporate, and unlike the other Companies of the City. ”
