The UCC 128 barcode is a variation of Code 128. While it uses nearly-identical encoding and symbology, it is distinctive for its use of a double start character to specify unique functions and encode unique data.
UCC 128 goes by several names including EAN-128 and UCC/EAN-128. After organizational changes which resulted in the Uniform Code Council (UCC) renamed as GS1, the UCC/EAN-128 specification was folded into the new GS1-128 barcode. While other terms are still used by organizations and barcode technology manufacturers, GS1-128 is now the most accurate name for the UCC 128 code.
As noted above, this barcode takes the bulk of its functionality from the older Code 128 specification, which allows excellent density for all-numeric data and good density for alpha-numeric data encodation. Just like their Code 128 counterparts, UCC 128 barcodes can be as long as necessary to store encoded data and can encode all 128 ASCII characters. As a result, they’re often preferred over older Code 39 barcodes for product data encoding.