a yarn of distinctive color, material, or twist, laid in a strand or strands of a rope to identify the owner or the maker.
What’s The #’s Real Name?A hash has referred to stripes on military jackets since as early as 1910. But, in the 1980s, people started using hash to refer to the # symbol.
Origin of rogue's yarn
First recorded in 1760–70
Also called identification thread.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019