Washington, Sept. 16 -- In another immigration-related legal setback for the Trump administration, a US court has blocked the government's attempt to tighten visa requirements on how long foreign students, exchange visitors and foreign journalists can study or work in America. The new visa rules were set to go into effect on September 15, before Monday's court order postponed the date pending further legal proceedings. The successful challenge to the visa restrictions was filed by an alliance of groups of educators and unions. Foreign students are presently allowed to remain in the United States legally so long as they maintain their student status, known as "duration of status". The Trump administration's new rules would have terminated the earlier policy and favoured a strict four-year student visa. P11...