|≈||approximately equal to|
|digits||indicates that digits repeat infinitely (e.g. 8.294 369 corresponds to 8.294 369 369 369 369 …)|
The barleycorn is a small English unit of length equal to 1⁄3 of an inch (i.e., close to 0.8467 cm) still used in Great Britain and Ireland as a determiner of shoe sizes.
The light-year is a unit of length used to express astronomical distances. It is about 9.5 quadrillion metres or 5.9 trillion miles. As defined by the International Astronomical Union (IAU), a light-year is the distance that light travels in vacuum in one Julian year (365.25 days). Because it includes the word "year", the term light-year is sometimes misinterpreted as a unit of time.