Ullage : Free space above a liquid contained in a tank, drum or tank-container, expressed as a percentage of the total capacity. Ullage is often used to leave room for possible expansion of the liquid
Sabelatrans Shipping Global SSG(Specialized in Shipping/Transportation of Heavy Lift, RoRo & Project forwarding by Sea , Air & Land), Shipping Terms, Ajman, UAE 2013. http://www.sabelatrans.com/shipping_terms.htm, (Log - Brit) {1030}