|≈||approximately equal to|
|digits||indicates that digits repeat infinitely (e.g. 8.294 369 corresponds to 8.294 369 369 369 369 …)|
The butt was a measure of liquid volume equalling two hogsheads. This equated to 108 imperial gallons (490 l) for ale or 126 imperial gallons (570 l) for wine (also known as a pipe).
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.