SKUs can no longer repeat in your shop

Every SKU is now unique in your shop. Set a code another product or variant already carries and the save is refused, with the field naming who uses it and a link to it. On the Variants tab the cell turns red. The code of a product with variants is a shared parent code and may match another. In an import - a spreadsheet, a Shopify export or a whole site - a code another item already carries, or an earlier row of the file already has, is not written: the product is imported without it (an updated one keeps its old code), and the preview names the holder. After the import, the Done step lists those products under "Refused SKUs", each with a field for a free code.