This excerpt taken from the AAPL 10-Q filed May 4, 2005.
Grant of Performance Shares. Subject to the terms and conditions of the Plan, Performance Shares may be granted to Participants at any time as shall be determined by the Administrator, in its sole discretion. Subject to Section 7(b) hereof, the Administrator shall have complete discretion to determine (i) the number of Shares subject to a Performance Share award granted to any Participant, and (ii) the conditions that must be satisfied, which typically will be based principally or solely on achievement of performance milestones but may include a service-based component, upon which is conditioned the grant or vesting of Performance Shares. Performance Shares shall be granted in the form of units to acquire Shares. Each such unit shall be the equivalent of one Share for purposes of determining the number of Shares subject to an Award. Until the Shares are issued, no right to vote or receive dividends or any other rights as a stockholder shall exist with respect to the units to acquire Shares.