U+0FD9 Tibetan Mark Leading Mchan Rtags

El Wikipedia tiene la siguiente información acerca de este punto de código:

The Tibetan script is a segmental writing system, or abugida, derived from Brahmic scripts and Gupta script, and used to write certain Tibetic languages, including Tibetan, Dzongkha, Sikkimese, Ladakhi, Jirel and Balti. It was originally developed c. 620 by Tibetan minister Thonmi Sambhota for King Songsten Gampo.

The Tibetan script has also been used for some non-Tibetic languages in close cultural contact with Tibet, such as Thakali, Nepali and Old Turkic. The printed form is called uchen script while the hand-written cursive form used in everyday writing is called umê script. This writing system is used across the Himalayas and Tibet.

The script is closely linked to a broad ethnic Tibetan identity, spanning across areas in India, Nepal, Bhutan and Tibet. The Tibetan script is of Brahmic origin from the Gupta script and is ancestral to scripts such as Lepcha, Marchen and the multilingual ʼPhags-pa script, and is also closely related to Meitei.