Undefined Fuel-reserved For Proprietary May 2026Though officially unconfirmed, several declassified military aviation documents reference a “Proprietary Reserve” of 7–12% total tank volume in certain special operations drones. The reserve is not accessible via standard fuel gauges and is isolated by a physical membrane. Pilots are instructed: | Step | Action | |------|--------| | | Identify the exact software/firmware version. | | 2 | Check localization files ( .po , .json , .resx , .strings ) for the key fuel.reserved.proprietary or similar. | | 3 | If found, correct the default value or add the missing translation. | | 4 | If not found, search the codebase for the hardcoded string "fuel-reserved" . | | 5 | Inspect CAN bus or MODBUS register maps for proprietary/unmapped IDs. | | 6 | Update the device firmware or the interpreting software (OBD scanner, dashboard). | | 7 | If it appears in a fleet API response, contact the vendor for a schema definition. | undefined fuel-reserved for proprietary The most common reason for seeing this message is . | | 2 | Check localization files ( And if you are a developer reading this: Future mechanics and drivers will thank you. | | 5 | Inspect CAN bus or When a system encounters a code that does not match these standards, it often defaults to an "undefined" state. The "reserved for proprietary" tag indicates that these specific data slots are intentionally left empty by standards bodies so that individual manufacturers—such as Gilbarco Veeder-Root or Worldpay —can implement their own specialized fuel products or additives without breaking the broader network’s logic. Technical and Operational Implications A fuel system reporting undefined could indicate: |