|≈||approximately equal to|
|digits||indicates that digits repeat infinitely (e.g. 8.294 369 corresponds to 8.294 369 369 369 369 …)|
The board-foot is a specialized unit of measure for the volume of lumber in the United States and Canada. It is the volume of a one-foot length of a board one foot wide and one inch thick.
Board-foot can be abbreviated FBM (for "foot, board measure"), BDFT, or BF. Thousand board-feet can be abbreviated as MFBM, MBFT, or MBF. Similarly, million board-feet can be abbreviated as MMFBM, MMBFT, or MMBF.
A barrel is one of several units of volume applied in various contexts; there are dry barrels, fluid barrels (such as the UK beer barrel and US beer barrel), oil barrels and so on. For historical reasons the volumes of some barrel units are roughly double the volumes of others; volumes in common usage range from about 100 to 200 litres (22 to 44 imp gal; 26 to 53 US gal).