Absent a specific reference in the IRC, you can find basically no way to get to the IBC. They ("we") did not even repeat the definition inside the IRC. Open up to interpretation; “to aid the motion of liquids”, the commentary invitations this as to avoid the accumulation of liquids; https://rylanygou52952.daneblogger.com/33821428/the-ultimate-guide-to-garage-ceiling-lifts-maximizing-space-and-convenience