As stated in subparagraph b of section 3 of Article 4, within the scope of Article 4, within the scope of the Tax Procedure Law Communiqué No. 527 on the conversion of old generation OPTs to new generation OPTs, the use of existing EFT-POS devices in the c-store can continue to process payment, as the date of the obligation to issue integrated receipts will become mandatory as of the next announcement to be specified by the Revenue Administration.