The document discusses various types of antitakeover measures that companies use to discourage unwanted hostile takeovers:
1. Poison pills allow existing shareholders to buy more shares at a discount, forcing down the value of the acquiring company's shares.
2. A white knight makes a friendly takeover offer to a target company facing a hostile takeover, providing an alternative to the hostile bid.
3. A management resignation threat can be effective if the existing management team is highly valued, as hostile takeovers often replace management.