N.Y. Not-For-Profit Corp. Law § 501

§ 501. Stock and shares prohibited; membership certificates authorized.\n A corporation shall not have stock or shares or certificates for stock\nor for shares, but may issue non-transferable membership certificates or\ncards to evidence membership, whether or not connected with any\nfinancial contribution to the corporation, as provided in section 601\n(Members). The fact that the corporation is a not-for-profit\ncorporation, and that the membership certificate or card is\nnon-transferable shall be noted conspicuously on the face or back of\neach such certificate or card.\n