Deduction interaction rules: amounts claimed under section 80CCD bar rebates under section 88 and deductions under section 80C. The amendment substitutes the provision to provide that amounts allowed as deductions under sub section (1) of section 80CCD cannot be used to claim a rebate under section 88 for prior assessment years and cannot be claimed as a deduction under section 80C for later assessment years, thereby preventing double use of the same payment across those reliefs and establishing a temporal application tied to assessment years.