This excerpt taken from the IDIX DEF 14A filed Apr 26, 2007.
Shares Subject to the Plan
Subject to certain adjustments, 3,000,000 shares of our common stock may be issued pursuant to the 2005 Plan. As of March 31, 2007, 2,684,537 shares of our common stock were subject to awards outstanding under the 2005 Plan.
If any award granted under the 2005 Plan is forfeited or the award otherwise terminates without the issuance of any shares, the shares associated with such award will be available for future grants subject, however, in the case of stock options to any limitations under the Internal Revenue Code of 1986, as amended, which we refer to as the Code. In addition, shares that are tendered to Idenix by a participant as payment of the exercise price of any stock option, or shares withheld from any award to satisfy a participants tax withholding obligations, will not count as shares issued under the 2005 Plan. In the event of stock dividends, stock splits, other recapitalizations, reclassifications or other specified events affecting us and shares of our common stock, appropriate and equitable adjustments shall be made to the number and kind of shares available for grant, as well as to other maximum limitations, under the 2005 Plan, and the number and kind of shares common stock or other rights and prices under outstanding awards.