It's a script attested from 2200~1700 years old inscriptions found in Central Asia, between what's today Kazakhstan and Afghanistan (both included). Discovered in the 1950s, but now freshly discovered inscriptions from Tajikistan (the Almosi inscriptions) encouraged people to take a further look at the decipherment, alongside older inscriptions (such as the Dašt-i Nāwur trilingual; written in Greek, Bactrian, and the unknown script).

This is specially interesting for those interested on Tocharian studies, as the language being deciphered might be potentially spoken by Tocharian speakers who migrated south.