How should the shoulder belt be positioned when using the booster seat?

The shoulder belt MUST cross midway between the child's shoulder and neck, must pass through the shoulder belt guide, and should be even with or just above the shoulders. In backless booster mode, if the vehicle's shoulder belt does not naturally cross midway between the child's shoulder and neck, you must use the shoulder belt clip to adjust it properly. The shoulder belt MUST NOT cross the child's neck or fall off the child's shoulder. (Pages 55, 59, 61)