Validation of Show Cause Notices restores retrospective proper officer status but limits adjudication by intelligence units. Amendment to Section 28 of the Customs Act retrospectively deems officers appointed under sub section (1) of section 4 to have always had the power of assessment under Section 17 and to have been the proper officers, thereby validating Show Cause Notices issued prior to the administrative notification. Officers of designated intelligence formations are administratively assigned proper officer functions but are directed not to exercise adjudicatory authority under clause (8) of Section 28; an earlier instruction to reissue certain notices is withdrawn and pending matters are to follow the amended statutory position.