Section 616. Greater requirement as to quorum and vote of shareholders

(a) The certificate of incorporation may contain provisions specifying
  either or both of the following:
    (1) That the proportion of votes of shares, or the proportion of votes
  of  shares of any class or series thereof, the holders of which shall be
  present in person or by proxy at any meeting of shareholders,  including
  a  special  meeting for election of directors under section 603 (Special
  meeting for election of directors), in order to constitute a quorum  for
  the  transaction  of  any business or of any specified item of business,
  including amendments to  the  certificate  of  incorporation,  shall  be
  greater than the proportion prescribed by this chapter in the absence of
  such provision.
    (2) That  the  proportion  of votes of shares, or votes of shares of a
  particular class or series of shares, that shall  be  necessary  at  any
  meeting  of  shareholders  for the transaction of any business or of any
  specified item of business, including amendments to the  certificate  of
  incorporation,  shall  be greater than the proportion prescribed by this
  chapter in the absence of such provision.
    (b) An amendment of the certificate of incorporation which changes  or
  strikes  out  a provision permitted by this section, shall be authorized
  at a meeting of shareholders by two-thirds of the votes  of  the  shares
  entitled  to  vote  thereon,  or  of such greater proportion of votes of
  shares, or votes of shares of a particular class or series of shares, as
  may be provided specifically in the  certificate  of  incorporation  for
  changing or striking out a provision permitted by this section.
    (c) If  the certificate of incorporation of any corporation contains a
  provision authorized by this section, the existence  of  such  provision
  shall  be  noted  conspicuously on the face or back of every certificate
  for shares issued by such  corporation,  except  that  this  requirement
  shall  not  apply  to  any  corporation  having  any class of any equity
  security  registered  pursuant  to  Section  twelve  of  the  Securities
  Exchange Act of 1934, as amended.