Tai Yo language

Tai Yo, also known as Tai Mène and Nyaw, is a Tai language of Southeast Asia. It is closely related to Tai Pao of Vietnam, where it may have originated. It was once written in a unique script, the Tai Yo script, but that is no longer in use. The language is known regionally in Laos and Thailand as "Tai Mène" and "Tai Nyaw" and, in Vietnam as "Tai Do" and "Tai Quy Chau". Superficially, Tai Yo appears to be a Southwestern Tai language but this is only because of centuries of language contact and it is properly classified with the Northern Tai languages. The "Nyaw"/"Nyo" spoken in central Thailand and western Cambodia is a dialect of Lao and not the same as Tai Yo.
Tai Mène.
The Mène people of Laos claim to be from Xieng Mène (also Xieng My) in Vietnam. These two names correspond to the following two towns in Nghệ An Province, Vietnam, located near Quỳ Châu (Chamberlain 1998).
Tai Mène appears to be related to Tai Pao ("paaw 4" < *"baaw A"), whose speakers claim to have originated from Tương Dương District, Nghệ An province, Vietnam (Chamberlain 1991). Tai Mène or related languages may have also been spoken in Thường Xuân District, Thanh Hóa, Vietnam by the Yo (Do) people (Robequain 1929).
Distribution.
Tai Mène is spoken in Borikhamxay Province, in many villages of Khamkeut District and several villages in Vieng Thong District (Chamberlain 1998). The Vietic languages Liha, Phong, Toum, Ayoy, Maleng, and Thaveung are spoken nearby.