GS1-128 was developed to provide a worldwide standard for exchanging data between different companies. GS1-128 not only encodes the data, but also provides a method of defining the meaning of the data by defining a list of "Application Identifiers" a.k.a. AIs.
UCC/EAN-128 is by itself not a symbology. It is a standard that defines what kind of data is, and how data is formatted. GS1-128 encodes data using Code128 symbology; therefore the printing requirement of Code128 symbology applies to GS1-128.
Every GS1-128 symbol encodes an AI to indicate that what type of data is encoded. In most of cases, AI also decides the length of the data and the format of the data. All dates are represented in the format YYMMDD. YY values between 51-99 indicates the years between 1951 and 1999. YY values between 00-50 indicates the years between 2000 and 2050.
If the AI numbers contain an 'x' or 'y', that means a single digit needs to be appended to the AI. x digit indicates the length of the following data field; y digit indicates the ordinal of the decimal point in the data field.
Table 1. List of Known AIs
| AI | Name | Constraint | Short Name |
|---|---|---|---|
| 00 | SSCC (Serial Shipping Container Code) | n2+n18 | SSCC |
| 01 | Global Trade Item Number | n2+n14 | GTIN |
| 02 | GTIN of Trade Items Contained in a logistic unit | n2+n14 | CONTENT |
| 10 | Batch or lot number | n2+an..20 | BATCH/LOT |
| 11 | Production date (YYMMDD) | n2+n6 | PROD DATE |
| 12 | Due date (YYMMDD) | n2+n6 | DUE DATE |
| 13 | Packaging date (YYMMDD) | n2+n6 | PACK DATE |
| 15 | Best before date (YYMMDD) | n2+n6 | BEST BEFORE or SELL BY |
| 17 | Expiration date (YYMMDD) | n2+n6 | USE BY OR EXPIRY |
| 20 | Product variant | n2+n2 | VARIANT |
| 21 | Serial number | n2+an..20 | SERIAL |
| 22 | Secondary data for specific health industry products | n2+an..29 | QTY/DATE/BATCH |
| 240 | Additional product identification assigned by the manufacturer | n3+an..30 | ADDITIONAL ID |
| 241 | Customer part number | n3+an..30 | CUST. PART NO. |
| 242 | Made-to-Order Variation Number | n2+n..6 | Variation Number |
| 250 | Secondary serial number | n3+an..30 | SECONDARY SERIAL |
| 251 | Reference to source entity | n3+an..30 | REF. TO SOURCE |
| 253 | Global Document Type Identifier | n3+n13+n..17 | DOC. ID |
| 254 | GLN Extension component | n3+an..20 | GLN EXTENSION |
| 30 | Variable count | n2+n..8 | VAR. COUNT |
| 310n-369n | (Trade and logistic measurements) | n4+n6 | -- |
| 337n | Kilograms per square metre | n4+n6 | KG PER m2 |
| 37 | Count of trade items contained in a logistic unit | n2+n..8 | COUNT |
| 390(n) | Amount payable - single monetary area | n4+n..15 | AMOUNT |
| 391(n) | Amount payable - with ISO currency code | n4+n3+n..15 | AMOUNT |
| 392(n) | Amount payable for a Variable Measure Trade Item - single monetary unit | n4+n..15 | PRICE |
| 393(n) | Amount payable for a Variable Measure Trade Item - with ISO currency code | n4+n3+n..15 | PRICE |
| 400 | Customer's purchase order number | n3+an..30 | ORDER NUMBER |
| 401 | Consignment number | n3+an..30 | CONSIGNMENT |
| 402 | Shipment Identification Number | n3+n17 | SHIPMENT NO. |
| 403 | Routing code | n3+an..30 | ROUTE |
| 410 | Ship to - deliver to Global Location Number | n3+n13 | SHIP TO LOC |
| 411 | Bill to - invoice to Global Location Number | n3+n13 | BILL TO |
| 412 | Purchased from Global Location Number | n3+n13 | PURCHASE FROM |
| 413 | Ship for - deliver for - forward to Global Location Number | n3+n13 | SHIP FOR LOC |
| 414 | Identification of a physical location Global Location Number | n3+n13 | LOC No |
| 415 | Global Location Number of the Invoicing Party | n3+n13 | PAY |
| 420 | Ship to - deliver to postal code within a single postal authority | n3+an..20 | SHIP TO POST |
| 421 | Ship to - deliver to postal code with Three-Digit ISO country code | n3+n3+an..9 | SHIP TO POST |
| 422 | Country of origin of a trade item | n3+n3 | ORIGIN |
| 423 | Country of initial processing | n3+n3+n..12 | COUNTRY - INITIAL PROCESS. |
| 424 | Country of processing | n3+n3 | COUNTRY - PROCESS. |
| 425 | Country of disassembly | n3+n3 | COUNTRY - DISASSEMBLY |
| 426 | Country covering full process chain | n3+n3 | COUNTRY - FULL PROCESS |
| 7001 | NATO stock number | n4+n13 | NSN |
| 7002 | UN/ECE meat carcasses and cuts classification | n4+an..30 | MEAT CUT |
| 703(s) | Approval number of processor with ISO country code | n4+n3+an..27 | PROCESSOR # s4 |
| 7003 | Expiration Date and Time | n4+n10 | EXPIRY DATE/TIME |
| 8001 | Roll products - width, length, core diameter, direction, and splices | n4+n14 | DIMENSIONS |
| 8002 | Electronic serial identifier for cellular mobile telephones | n4+an..20 | CMT No |
| 8003 | Global Returnable Asset Identifier | n4+n14+an..16 | GRAI |
| 8004 | Global Individual Asset Identifier | n4+an..30 | GIAI |
| 8005 | Price per unit of measure | n4+n6 | PRICE PER UNIT |
| 8006 | Identification of the component of a trade item | n4+n14+n2+n2 | GCTIN |
| 8007 | International Bank Account Number | n4+an..30 | IBAN |
| 8008 | Date and time of production | n4+n8+n..4 | PROD TIME |
| 8018 | Global Service Relation Number | n4+n18 | GSRN |
| 8020 | Payment Slip Reference Number | n4+an..25 | REF No |
| 8100 | GS1-128 Coupon Extended Code - NSC + Offer Code | n4+n1+n5 | - |
| 8101 | GS1-128 Coupon Extended Code - NSC + Offer Code + end of offer code | n4+n1+n5+n4 | - |
| 8102 | GS1-128 Coupon Extended Code - NSC | n4+n1+n1 | - |
| 90 | Information mutually agreed between trading partners (including FACT DIs) | n2+an..30 | INTERNAL |
| 91-99 | Company internal information | n2+an..30 | INTERNAL |