Which abbreviation indicates a vehicle's operational status during an inspection?

The abbreviation that indicates a vehicle's operational status during an inspection is "O/S," which stands for "Out of Service." This designation is critical within commercial vehicle inspections as it signifies that a vehicle is not deemed safe to operate due to identified defects or violations that must be addressed before the vehicle can return to service.

Understanding operational status is essential for ensuring vehicle safety and compliance with regulations. Other abbreviations, while relevant in different contexts—such as "AC" typically referring to air conditioning, "OP" possibly denoting operational or operating parameters, and "IN" which might indicate in service or inspection—do not specifically convey the state of a vehicle being unfit for operation as "O/S" does. Thus, "O/S" is fundamentally connected to the determination of safety and readiness for road use in commercial vehicle inspections.