What does O/S stand for in vehicle inspection terminology?

In vehicle inspection terminology, O/S stands for "Out of Service." This designation is applied when a vehicle is deemed unsafe to operate due to significant mechanical issues, safety violations, or other critical factors that could compromise the safety of the driver, passengers, or others on the road. When a vehicle is labeled as Out of Service, it is taken off the road until the necessary repairs or adjustments are made to address the identified issues. This ensures that vehicles meet safety standards and regulations, thus playing a crucial role in maintaining road safety and compliance with traffic laws.

The other terms, while they may sound plausible, do not accurately capture the specific regulatory context and implications associated with the O/S designation.