Editing Shareholder rights plan (section)

==== Voting plan ====
{{Main|Voting plan}}
In a [[voting plan]], a company will charter preferred stock with superior voting rights over that of common shareholders. If an unfriendly bidder acquired a substantial quantity of the target firm's voting common stock, it then still would not be able to exercise control over its purchase. For example, [[ASARCO]] established a voting plan in which 99% of the company's common stock would only harness 16.5% of the total voting power.<ref>{{cite journal |last1=Malatesta |first1=Paul H. |last2=Walkling |first2=Ralph A. |title=Poison pill securities |journal=Journal of Financial Economics |date=January 1988 |volume=20 |pages=347–376 |doi=10.1016/0304-405X(88)90050-5 }}</ref>

In addition to these pills, a "dead-hand" provision allows only the directors who introduce the poison pill to remove it (for a set period after they have been replaced), thus potentially delaying a new board's decision to sell a company.