Job work transitional relief: no tax if pre existing inputs or goods are returned within prescribed period, subject to declaration. Section 141 exempts tax on inputs, semi finished goods or goods sent for testing to job workers or other premises before the appointed day where such items are returned to the principal place within six months (extendable by two months by the Commissioner); failure to comply triggers recovery of input tax credit under clause (a) of sub section (8) of section 142. Transfers to registered premises for supply or export are permitted within the period, and exemption is conditional on prescribed declarations by the consignor and the job worker of goods held on the appointed day.