Scrutiny of returns: officers may flag discrepancies and require explanations, then initiate assessment if not satisfactorily addressed. Scrutiny of returns empowers the proper officer to examine returns and related particulars, notify discrepancies, and seek explanations; an acceptable explanation closes the matter. If no satisfactory explanation is furnished within thirty days or an authorised extension, or the taxpayer accepts discrepancies but fails to correct them in the subsequent return, the proper officer may initiate further actions or proceed to determine tax and other dues under assessment and re-assessment provisions.