U+AADF "꫟" Tai Viet Symbol Koi Koi Unicode Character

U+AADF "꫟" Tai Viet Symbol Koi Koi is a rare typographic mark used in the Tai Viet script, which is employed primarily by the Tai Dam, Tai Don, and Tai Daeng communities in Vietnam, Laos, and parts of China. This specific symbol, known as "Koi Koi," functions as a repetition or abbreviation indicator, somewhat akin to a ditto mark, signaling that a preceding word or phrase is to be repeated in written text. It is a non-alphabetic character that aids in concise writing, but is considered obscure or archaic in modern usage, leading to limited support in digital fonts and encoding systems. The character was added to Unicode in 2008 as part of the Tai Viet block, helping to preserve the traditional writing practices of these ethnic groups in the digital age.