Proper officer designation under Customs Act assigns officer ranks to exercise listed statutory customs functions, clarifying delegation and supersession. Designation of proper officer under the Customs Act assigns specified officer ranks and officers above them in rank to exercise enumerated enforcement, assessment, examination, clearance and intelligence functions at ports, airports, land customs stations, warehouses and preventive posts. The notification supersedes the earlier instrument insofar as stated and provides that assigned functions (other than at the highest Commissioner level) are to be exercised pursuant to the statutory delegation mechanism; it comes into force on publication in the Official Gazette.