Retired in ISO 639-3: Merge into Achang [acn]
Excerpt from change request document:
This is a subdialect of the Husa dialect of Achang. According to a native speaker of Husa Achang, it is very easily mutually intelligible with Husa Achang and its speakers only recently moved away from the Husa valley.
Xiandao is a subdialect of the Husa dialect of Achang and should be included in the element [acn].