With the POS module a Barcode field appears in the meal editor. Leave it empty and Sprwt generates one automatically when you save; a barcode image preview is shown under the field. The format comes from Business: Cart > Meal Barcode Format: UPC-A (12-digit retail) builds a code from the UPC-A Barcode Prefix (5 digits, default 20000) plus the meal ID and a check digit, while Code 128 (alphanumeric) produces MEAL-000123. You can also type your own value (up to 30 characters). Barcodes are kept unique across meals.