The federal government's Nondiscrimination Policy reads, in part, as follows:  "In accordance with Federal law and U.S. Department of Agriculture policy, this institution is prohibited from discriminating on the basis of race, color, national origin, sex, age or disability." 

The Administrator's Reference Manual addresses the issue of non-discrimination, and is being updated to state explicitly that schools may not actively seat children in alternating genders.  Specifically, the updated ARM will state, "There must not be any discrimination on the basis of race, color, national origin, age, sex or disability in the application approval process, selection of applications for verification, or separation in the eating periods, seating arrangements, serving line and eating areas, i.e., boy-girl, boy-girl."