The Department of Homeland Security said Wednesday it intends to publish a proposed rule that would limit the length of time foreign students are allowed to stay in the United States. Since 1978, foreign students, or F visa holders, could stay in the U.S. for their “duration of status,” meaning as long as they were enrolled as a full-time student. The proposed rule would allow for foreign students and exchange visitors to stay up to the duration of the program they are participating in, not to exceed a 4-year period.