Administrative instructions ensure uniform GST implementation; circulars bind officers though statute prevails over conflicting guidance. Section 168 empowers the Board to issue orders, instructions or directions to CGST officers to secure uniformity in implementation; such directions are binding on officers though generally not on taxpayers, and statutory provisions prevail over conflicting instructions. The provision identifies the Commissioner (or Joint Secretary posted in the Board with Board approval) as the official authorised to exercise specified delegated powers in areas including designation of proper officers, delegation of Commissioner functions, notifications for unique identity numbers, accounting and filing accommodations, time-limit extensions for returns and statements, job-work procedures, collection of statistics, and limited disclosure exceptions.