Retired in ISO 639-3: Merge into Lipo [lpo]
Excerpt from change request document:
The distinctions between these two varieties has been a matter of some confusion for decades. This is primarily due to the fact that [yio] speakers are officially classified under the Yi nationality and [lpo] speakers are officially classified under the Lisu nationality. Numerous complex geographic, sociolinguistic, cultural and historical factors are behind this distinction--none of which seem to be directly related to the inter-intelligibility and/or in- group identity of the Lipo speakers themselves. Bradley has engaged in extensive research on Lipo dialects as part of his larger research focus on Central Ngwi varieties in general. Based on his own on-site survey work, he has observed the two to be mutually intelligible dialects of the same language and closely aligned ethnically in spite of an otherwise highly ramified sociolinguistic situation linked to various group-external factors.