witness mark n. generally, an intentional, accidental, or naturally occurring spot, line, groove, or other contrasting area that serves as an indicator of certain facts; in geography and surveying, a blaze, cut, hole, paint splash, or message written on a post, tree, rock or other guide to indicate a boundary, feature, or significant point on land, especially on a witness post; in construction and manufacturing, a line, groove, score, notch, cut, or written indicator made on the surface of material to impart information, such as where to cut or join; in forensic investigation, a surface groove, smear, stain, abrasion or other feature that can serve as evidence. (source: Double-Tongued Dictionary)
Further reading
It was a dark and stormy night. So begins the long and increasingly convoluted prose of Edwards Bulwer-Lytton’s best-known novel. Today the annual Bulwer-Lytton Contest asks contestants for fanciful first sentences that are similarly...
Enthusiastic book recommendations! Martha’s savoring the biography of Alexander von Humboldt, the 19th-century explorer, polymath, and naturalist who revolutionized our understanding of nature and predicted the effects of human activity on...
In process engineering, a witness mark can be the result of a particular process, the presence of which will prove that the process has occurred. E.g. A mark left on a test point from a test probe. However, in some circumstances, such marks are considered to be damaging and so efforts are made to avoid, prevent or eradicate such marks.