The Chief Rabbinate released, Sunday evening, detailed instructions for Passover kashrut and grocery chains. It said a product's kashrut should be printed on its package and not on a sticker, although stickers would be allowed if approved ahead of time in writing by the rabbi giving the certification.
The rabbinate said similar-looking kosher-for-Passover and non-kosher-for-Passover products should not be next to each other on the shelf. Leavened products, which are banned during the holiday, should be hidden in a strong cover to avoid their being sold during the holiday. Similarly, the barcode of a leavened product should be blocked so it cannot be sold.