Technical manuals for hardware like the Gasboy EMV system list these as "Undefined Fuel" blocks reserved for future or private use.
Modern systems use or resource bundles for localization. For example:
Allowing a specific fleet or retailer to use a custom product code that isn't part of the public standard. Internal Routing: undefined fuel-reserved for proprietary
Fuel Other (Standard Def any fuel product that can not be classified. Tax exempt program does not exempt taxes for this code.) Squarespace FLEET CARDS – REPORTING OF ALTERNATIVE FUELS
The global shift toward alternative energy frequently outpaces retail POS software updates. Universal reporting relies on rigid NACS category sheets. When a station introduces a novel blend—such as a specific hydrogen mix, high-density biodiesel, or localized ethanol variations—the pump may transmit an unassigned product code. Rather than rejecting the payment entirely, the transaction processor passes it through under the "Undefined Fuel" umbrella. 2. Private and Commercial "Cardlock" Networks Technical manuals for hardware like the Gasboy EMV
Locate the fuel sensor along the fuel line under the vehicle. Inspect the wiring harness for signs of fraying, cracking, or corrosion from road debris. Clean the connector with electrical contact cleaner. Step 4: Check for Fuel Contamination
Sometimes the issue is purely mechanical. A gas station may update its pumps or install a new additive blend but fail to correctly map the internal product codes within its local POS terminal. When the network receives a corrupted or unmapped numerical string, the fallback algorithm labels the item as an undefined fuel type. Tax and Accounting Implications for Fleet Managers Internal Routing: Fuel Other (Standard Def any fuel
Moreover, there is the question of energy security. If critical systems rely on a fuel that only one company or nation can define and supply, the supply chain becomes a geopolitical lever.
However, when that product is assigned to a generic "undefined proprietary" code in a merchant's point-of-sale system, the manufacturer risks losing control over their trade secret. The "reserved for proprietary" code acts as a . It allows the transaction to be flagged as "special fuel—additized with proprietary additive," without revealing the specific chemical makeup (additive type not determined or P=proprietary) to the cashier or customer. This ensures legal compliance while safeguarding intellectual property.