Extended reassessment notices treated as show cause under section 148A, triggering new law procedure and reply rights. Extended reassessment notices issued during the extension period are to be treated as show cause notices under the new section 148A and processed under the new reassessment regime. The Assessing Officer must provide the information and material relied upon within the prescribed short period (with specified exclusions for cases below the monetary threshold), allow the assessee a limited reply with possible extension, and then pass a reasoned order under the new procedure with prior specified authority approval before issuing any fresh notice or serving an order declining issuance.