| 2 | Dun's SIC 2+2, Dun & Bradstreet |
| A | Schedule A, Tariff Schedules of the United States Annotated |
| B | U.S. Foreign Trade Schedule B, Statistical Classification of Domestic and Foreign Commodities Exported from the United States |
| C | Canadian Freight Classification |
| D | Department of Defense Unique Codes |
| E | Coordinated Motor Freight Classification |
| F | National Stock Number |
| G | Canadian Wheat Board, Grain Code for Terminal Elevator Accounting |
| H | Brussels Nomenclature |
| I | Milstamp AITC or Water Commodity Code |
| J | Harmonized Code System (United States) |
| K | Federal Supply Classification |
| L | Last Contained Contents STCC |
| N | National Motor Freight Classification (NMFC) |
| P | Bulk Petroleum Codes |
| Q | Quota Category |
| S | Standard International Trade Classification (SITC) |
| T | Standard Transportation Commodity Code (STCC) |
| U | Uniform Freight Classification (UFC) |
| V | Standard Industrial Classification (SIC) Code |
| Z | Mutually defined. |