Proposal to encode the Old Sogdian script in Unicode

This is a proposal to encode the Old Sogdian script into the Unicode Standard. The script was published in Unicode version 11.0 in 2018. Old Sogdian was used in the Kultobe inscriptions, the 'Ancient Letters' of Dunhuang, China, the upper Indus inscriptions dated from 4-7c CE, and on inscribed coins and vessels from the area of Chach (modern Tashkent, Uzbekistan)