Section 620 - Agreements as to voting; provision in certificate of incorporation as to control of directors(a) An agreement between two or more shareholders, if in writing and signed by the parties thereto, may provide that in exercising any voting rights, the shares held by them shall be voted as therein provided, or as they may agree, or as determined in accordance with a procedure agreed upon by them.(b) A provision in the certificate of incorporation otherwise prohibited by law because it improperly restricts the board in its management of the business of the corporation, or improperly transfers to one or more shareholders or to one or more persons or corporations to be selected by him or them, all or any part of such management otherwise within the authority of the board under this chapter, shall nevertheless be valid:(1) If all the incorporators or holders of record of all outstanding shares, whether or not having voting power, have authorized such provision in the certificate of incorporation or an amendment thereof; and(2) If, subsequent to the adoption of such provision, shares are transferred or issued only to persons who had knowledge or notice thereof or consented in writing to such provision.(c) A provision authorized by paragraph (b) shall be valid only so long as no shares of the corporation are listed on a national securities exchange or regularly quoted in an over-the-counter market by one or more members of a national or affiliated securities association.(d)(1) Except as provided in paragraph (e), an amendment to strike out a provision authorized by paragraph (b) shall be authorized at a meeting of shareholders by (A) (i) for any corporation in existence on the effective date of subparagraph (2) of this paragraph, two-thirds of the votes of the shares entitled to vote thereon and (ii) for any corporation in existence on the effective date of this clause the certificate of incorporation of which expressly provides such and for any corporation incorporated after the effective date of subparagraph (2) of this paragraph, a majority of the votes of the shares entitled to vote thereon or (B) in either case, by such greater proportion of votes of shares as may be required by the certificate of incorporation for that purpose.(2) Any corporation may adopt an amendment of the certificate of incorporation in accordance with the applicable clause or subclause of subparagraph (1) of this paragraph to provide that any further amendment of the certificate of incorporation that strikes out a provision authorized by paragraph (b) of this section shall be authorized at a meeting of the shareholders by a specified proportion of votes of the shares, or votes of a particular class or series of shares, entitled to vote thereon, provided that such proportion may not be less than a majority.(e) Alternatively, if a provision authorized by paragraph (b) shall have ceased to be valid under this section, the board may authorize a certificate of amendment under section 805 (Certificate of amendment; contents) striking out such provision. Such certificate shall set forth the event by reason of which the provision ceased to be valid.(f) The effect of any such provision authorized by paragraph (b) shall be to relieve the directors and impose upon the shareholders authorizing the same or consenting thereto the liability for managerial acts or omissions that is imposed on directors by this chapter to the extent that and so long as the discretion or powers of the board in its management of corporate affairs is controlled by any such provision.(g) If the certificate of incorporation of any corporation contains a provision authorized by paragraph (b), the existence of such provision shall be noted conspicuously on the face or back of every certificate for shares issued by such corporation.N.Y. Bus. Corp. Law § 620