Some products sold by retailers outside United States and Canada have been using EAN-13 codes beginning with 0, since they were generated by GS1-US.
The 020-029 GS1 Prefixes are worth a special mention. GS1 defines this as being available for retailer internal use (or internal use by other types of business). Some retailers use this for proprietary (own brand or unbranded) products, although many retailers obtain their own Manufacturer Code for their own brands. Other retailers use at least part of this prefix for products which are packaged in store, for example, items weighed and served over a counter for a customer. In these cases, the barcode may encode a price, quantity or weight along with a product identifier - in a retailer defined way. The product identifier may be one assigned by the Produce Electronic Identification Board (PEIB) or may be retailer assigned. Retailers who have historically used UPC barcodes tend to use GS1 prefixes starting with "02" for store-packaged products.citation needed
The EAN "country code" 978 (and later 979) has been allocated since the 1980s to reserve a Unique Country Code (UCC) prefix for EAN identifiers of published books, regardless of country of origin, so that the EAN space can catalog books by ISBN rather than maintaining a redundant parallel numbering system. This is informally known as "Bookland". The prefix 979 with first digit 0 is used for International Standard Music Number (ISMN) and the prefix 977 indicates International Standard Serial Number (ISSN).