Edmondson & Gregerson (1996)[3] listed many phonological and lexical similarities shared by Bolyu and Vietic languages.
However, Gérard Diffloth later suggested that Pakanic (i.e., Bolyu and Bugan) shares an affinity with Palaungic languages and was part of a wider Northern Mon-Khmer group.
Mangic, a proposed language grouping that includes Mang as a sister to Pakanic within a unified subgroup of Austroasiatic, is recognized by Ilia Peiros (2004) and Sidwell's earlier classifications.
Proto-Pakanic, the proto-language ancestral to Bolyu and Bugan but not Mang, was reconstructed by Andrew Hsiu (2016).
[4] Hsiu (2017),[5] citing Li Xulian (1999), notes that Pakanic languages were formerly spoken further up north in Guizhou and were in close contact with Gelao.