Section 153C: amended trigger applies if seized material is received post amendment, widening third party assessment scope.
The substituted text widens the jurisdictional trigger for third party assessments from strict ownership to where books or documents "pertain to" or contain information that "relates to" the other person; the first proviso's deeming fiction makes the date of receipt of seized material by the other person's Assessing Officer the operative reference point, so if receipt, satisfaction and issuance of notice occur after the amendment, the amended provision governs, subject to the requirement of recorded satisfaction that the material bears on determination of total income.