All persons who separate and refine gold, silver or platinum for the trade, as well as auctioneers, ministerial officers or any other bodies (auction rooms, municipal credit institutions, etc.) carrying out, even occasionally, sales or auctions of worked or unworked gold, silver or platinum materials, intermediaries, room workers, setters, polishers, etc., and, in general, all persons who hold materials of this type for the exercise of their profession, are required to declare this to the guarantee office to which they belong, and, in general, all persons who hold materials of this type for the exercise of their profession, are required to make a declaration to the office of guarantee to which they belong; a register of the said declarations shall be kept and copies issued if necessary.