Repeal of Delhi sales tax rules preserves vested rights and deems prior administrative acts valid under the new rules. The rule repeals specified Delhi sales tax rules while preserving their prior operation: rights, titles, obligations and liabilities already acquired, accrued or incurred under those rules remain unaffected, and acts, appointments, notifications, notices, orders, rules, forms or certificates made under the repealed rules are deemed to have been done under these Rules to ensure continuity.