The vertical and horizontal light distribution of the fixed obstruction lights should meet the requirements specified in the pertinent specifications listed in this publication. The vertical light distribution of the flashing and rotating hazard beacons should be such that the time-intensity integral of the flashes at angles between one degree and three degrees above the horizontal is not less than the candle-seconds values specified hereinbefore under "intensity of lighting," and the time-intensity integral at angles between three degrees and fifteen degrees above the horizontal is not less than the product of these candle-seconds values multiplied by nine over the square of the numerical value in degrees of the angle above the horizontal.