See Table C9.T4.
Mandatory for Foreign Military Sales (FMS) Letters of Offer and Acceptance (LOAs) when a Nonrecurring Cost (NC) charge (known as a "Special NC") is being collected on behalf of another country.
Mandatory for Amendments and Modifications when lines are added and the special NC charge applies to the new lines; or quantities are increased on lines where a special NC charge applies.
"Special Nonrecurring Costs (NC) apply to line(s) insert numbers] of this Foreign Military Sales (FMS) case and are included within the cost of the line. These costs are being collected on behalf of another country and cannot be waived by the U.S. Government."