""Manipuri Language" means Meeteilon written in Meetei Mayek and spoken by the majority of Manipur population: Provided that the concurrent use of Bengali Script and Meetei Mayek shall be allowed in addition to English language, for a period upto 10(ten) years from the date of commencement of this Act."
January 1, 1970
https://en.wikiquote.org/wiki/Meitei_language