|≈||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 link (usually abbreviated as "l.", "li." or "lnk."), sometimes called a Gunter’s link, is a unit of length formerly used in many English-speaking countries. A link is exactly 66⁄100 of a foot, or exactly 7.92 inches or 20.1168 cm.