A near miss in forklift operations is an unplanned event that caused no injury or damage but could have with a small change in timing or position. Typical examples are a forklift passing a pedestrian at close range, two trucks braking hard at a blind intersection, a load shifting or falling from the forks without hitting anyone, and a person walking under raised forks. Sites set their own working definition, often based on distance, speed and whether the person was in the operator's line of sight, so that events are recorded the same way by everyone.
The full guide is what is a near miss. For forklift work, a usable definition names the parties (truck and person, or truck and truck), the trigger (separation below an agreed distance while the truck is moving, an emergency stop, a dropped load) and a severity scale.
Severity should reflect potential: a close pass at walking pace is not the same as one at travel speed with a raised load. Write the definition down, train supervisors on it and apply it to both manual reports and any automatic detection data, so the two sources can be compared.