Examples: “The vehicle shall meet the requirements of S4.1 when tested at any point between 18 and 22 inches above the ground.” This means that the vehicle must be capable of meeting the specified requirements at every point between 18 and 22 inches above the ground. The test in question for a given vehicle may call for a single test (a single impact, for example), but the vehicle must meet the requirement at whatever point the Administration selects, within the specified range.

“Each tire shall be capable of meeting the requirements of this standard when mounted on any rim specified by the manufacturer as suitable for use with that tire.” This means that, where the manufacturer specifies more than one rim as suitable for use with a tire, the tire must meet the requirements with whatever rim the Administration selects from the specified group.

“Any one of the items listed below may, at the option of the manufacturer, be substituted for the hardware specified in S4.1.” Here the wording clearly indicates that the selection of items is at the manufacturer's option.