This excerpt taken from the WPI 10-K filed Mar 10, 2006.
Stock repurchase program
On February 15, 2006, the Board authorized the expenditure of an additional $300.0 million to repurchase shares of the Companys outstanding common stock. The repurchases will be made in open market or privately negotiated transactions from time to time in compliance with the Securities and Exchange Commissions Rule 10b-18, subject to market conditions, applicable legal requirements and other factors. Additionally, the Board has authorized that purchases may be made under Rule 10b5-1 promulgated under the Securities and Exchange Act of 1934, as amended. A Rule 10b5-1 plan allows Watson to repurchase its shares during periods when it would normally not be active in the market due to its internal trading blackout periods. All such purchases must be made in accordance with a pre-defined plan that is established when the plan administrator is not aware of any material non-public information.