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Gérard Diffloth reconstructed Proto-Waic in a 1980 paper. His classification is as follows (Sidwell 2009). (Note: Individual languages are highlighted in italics.)
The recently discovered Meung Yum and Savaiq languages of Shan State, Burma also belong to the Wa language cluster.
Other Waic languages in Shan State, eastern Myanmar are En and Siam (Hsem), which are referred to by Scott (1900) as En and Son. Hsiu (2015) classifies En, Son, and Tai Loi in Scott (1900) as Waic languages, citing the Waic phonological innovation from Proto-Palaungic *s- > h- instead of the Angkuic phonological innovation from Proto-Palaungic *s- > s-.
Shintani Tadahiko. 2016. The Va (En) language. Linguistic survey of Tay cultural area (LSTCA) no. 108. Tokyo: Research Institute for Languages and Cultures of Asia and Africa (ILCAA).