Certain vessels are assigned timber freeboards, but before these can be assigned, certain additional conditions have to be met. One of these conditions is that the vessel must have a forecastle of at least 0.07 the length of the vessel and of not less than standard height, which is 1.8 metres for a vessel 75 metres or less in length and 2.3 metres for a vessel 125 metres or more in length with intermediate heights for intermediate lengths. A poop or raised quarter deck is also required if the length is less than 100 metres. The letter "L" prefixes the load line marks to indicate a timber load line. Except for the timber winter North Atlantic freeboard, the other freeboards are less than the standard freeboards. This allows these ships to carry additional timber as deck cargo, but with the facility to jettison this cargo.