This excerpt taken from the NKE 10-Q filed Jan 7, 2009.
Amending Participation. After a participant has begun participating in the Plan by initiating payroll deductions, the participant may amend the payroll deduction authorization (i) once during any Offering to decrease the amount of payroll deductions, and (ii) effective for the first paycheck of a new Offering to either increase or decrease the amount of payroll deductions. A request for a decrease in payroll deductions during an Offering must be submitted to the Company in a form specified by the Company no later than the Change Deadline (as defined below) for that Offering, and shall be effective for any paycheck only if the request is received by the Company no later than the last business day of the immediately preceding calendar month, or by such other deadline as may be established from time to time by the Authorized Officer for defined groups of employees. A request for an increase or decrease in payroll deductions effective for the first paycheck of a new Offering must be submitted to the Company in a form specified by the Company no later than the Subscription Deadline for the new Offering. In addition, if the amount of payroll deductions from any participant during an Offering exceeds the maximum amount that can be applied to purchase shares in that Offering under the limitations set forth in paragraph 5(b) above, then (x) as soon as practicable following a written request from the participant, payroll deductions from the participant shall cease and all such excess amounts shall be refunded to the participant, and (y) payroll deductions from the participant shall restart as of the commencement of the next Offering at the rate set forth in the participant’s then effective payroll deduction authorization. If the Authorized Officer provides an alternative to payroll deduction as a method of contributing to the Plan in any jurisdiction, the Authorized Officer shall also specify terms for amending contribution levels in that jurisdiction.