|≈||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).
Lambda (written λ, in lowercase) is a legitimate metric unit of volume equal to 10−9 m3, 1 cubic millimeter (mm3) or 1 microlitre (µL). Introduced by the BIPM in 1880, the lambda has been used in chemistry and in law for measuring volume, but its use is not recommended.