In March 1989, a (B)TRON-based system was adopted by Japanese government organizations "Center for Educational Computing" as the system of choice for school education including compulsory education. However, in April, a report titled "1989 National Trade Estimate Report on Foreign Trade Barriers" from Office of the United States Trade Representative have specifically listed the system as a trade barrier in Japan. The report claimed that the adoption of the TRON-based system by the Japanese government is advantageous to Japanese manufacturers, and thus excluding US operating systems from the huge new market; specifically the report lists MS-DOS, OS/2 and UNIX as examples. The Office of USTR was allegedly under Microsoft's influence as its former officer Tom Robertson was then offered a lucrative position by Microsoft. While the TRON system itself was subsequently removed from the list of sanction by Section 301 of the Trade Act of 1974 after protests by the organization in May 1989, the trade dispute caused the Ministry of International Trade and Industry to accept a request from Masayoshi Son to cancel the Center of Educational Computing's selection of the TRON-based system for the use of educational computers. The incident is regarded as a symbolic event for the loss of momentum and eventual demise of the BTRON system, which led to the widespread adoption of MS-DOS in Japan and the eventual adoption of Unicode with its successor Windows.