BanglaCapsule | Chittagong Timeline  

1998 The government constitutes an interim Chittagong Regional Council entrusting with the task of maintaining law and order, levying taxes and overseeing development projects in the Chittagong region.
Google
2018 British era English spelling of Chittagong was changed to Chattogram to make them sound similar to the Bangla alphabet by National Implementation Committee for Administrative Reorganisation-Reform (NICAR).
Google