N.Y. GCT Law § 45-B*2

* § 45-b. Further requirements relating to the business of plumbing.\n1. No person otherwise qualified shall engage in the trade, business or\ncalling of a plumber or of plumbing in a city of this state as employing\nor master plumber until he has first procured from the board of health\nor the examining board of plumbers if so designated by local law in such\ncity a metal plate or sign appropriately lettered or marked "licensed\nplumber;" such plate or sign to be conspicuously posted in the window of\nthe place where such business is conducted. Any person retiring,\nabandoning or not actually engaged in such trade, business or calling\nhereinbefore mentioned, shall surrender to the board of health or the\nexamining board of plumbers if so designated by local law of the city\nsuch metal plate or sign and shall not again engage in such trade,\nbusiness or calling until he has again procured a metal sign as herein\nprovided.\n 2. Within thirty days after this section takes effect, the board of\nhealth or the examining board of plumbers if so designated by local law\nin every city of this state shall prepare metal plates or signs, at\nleast fourteen inches wide and not less than twenty-two inches in length\nappropriately lettered or marked "licensed plumber," the lines of each\nletter to be four inches long and five-eighths of an inch wide; such\nplate or sign shall, on some part thereof, contain an identification\nnumber, which number together with the name and location of the place of\nbusiness of the person to whom issued shall be recorded in the office of\nsuch board of health or the examining board of plumbers if so designated\nby local law. Every person now actually engaged or about to engage in\nthe trade, business or calling of a plumber or of plumbing as employing\nor master plumber, who has otherwise complied with the provisions of law\nrelating to the conduct of such business upon the payment of five\ndollars to the board of health or the examining board of plumbers if so\ndesignated by local law of such city shall have issued to him a sign or\nplate hereinbefore described. Any person to whom such plate or sign has\nbeen issued who shall loan, rent, sell or transfer the same to another\nperson whether such person be entitled to receive a similar plate or\nsign or not, or otherwise wilfully violates the provisions of this\nsection shall be guilty of a misdemeanor punishable by a fine of not\nexceeding fifty dollars for the first offense, and not less than one\nhundred dollars nor more than five hundred dollars for a subsequent\noffense, and in addition thereto shall forfeit his license and\ncertificate of qualifications.\n The provisions of this section shall apply to all cities of the state,\nexcluding the city of New York.\n * NB There are 2 § 45-b's\n