Zero-rated supply: sending goods abroad for exhibition is not zero-rated; invoicing on sale or non-return triggers export treatment. Sending or taking goods out of India for exhibition or on consignment is not a supply under section 7 and therefore not a zero-rated supply under section 16; specified goods must be accompanied by a delivery challan under rule 55 and records maintained. No bond or LUT is required. Supplies occur on the date of sale abroad for quantities sold within the stipulated period, or on expiry of that period for unsold/unreturned quantities; tax invoices must be issued accordingly under sections 12 and 31 read with rule 46. Refunds of input tax credit may be claimed after invoicing if eligible under section 54(3) and rule 89(4).