This excerpt taken from the NDAQ DEF 14A filed Apr 3, 2009.
Other Tax Policies
Section 409A of the Code imposes additional taxes on taxpayers who have certain nonqualified deferred compensation arrangements with the company. To assist in preventing the imposition of additional tax under Section 409A, the management compensation committee undertook an extensive review of the plans and agreements underlying NASDAQ OMXs executive compensation program in 2008. Subsequently, the committee approved various immaterial changes, effective December 31, 2008, to certain plans and agreements to bring them into compliance with Section 409A of the Code.