Affirmative-action policies at Harvard University have been challenged in court. The suit against Harvard alleges that the university limits the number of Asian-Americans it admits each year, arguing that white, black, and Hispanic applicants are given preferences over better-qualified Asian-American applicants. The suit was filed Monday in Boston by the Project on Fair Representation. The plaintiff in both lawsuits is Students for Fair Admissions, a nonprofit whose members include students recently denied admission. The university did not respond to requests for comment.