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.