Assessment scheme powers permit centralised, technology-driven, team-based assessments under notification with parliamentary oversight and specified modifications. A proviso to section 143(1)(a) bars adjustments under the specified sub-clause for returns from the referenced assessment year. The Central Government may, by notification, frame a scheme under new sub-section (3A) to make assessments under section 143(3) to enhance efficiency by removing officer-assessee interface where feasible, optimising resources, and creating a team-based assessment regime; notifications under sub-section (3B) may disapply or modify assessment provisions subject to a temporal limit, and every such notification must be laid before Parliament under sub-section (3C).