Block Period definition governs scope of search-based assessments, specifying preceding assessment years and inclusion up to last search authorization. Block Period covers the previous years relevant to multiple assessment years before the year in which a search or requisition is initiated and includes the period from the first of April of that year up to the execution date of the last authorization for the search or requisition. Undisclosed Income includes money, bullion, jewellery, virtual digital assets, other valuable articles, expenditures, entries in books or transactions representing income or property not disclosed under the Act, and any incorrect expense, exemption, deduction or allowance found in respect of the block period.