Excerpt from change request document:
Hmong Njua [blu] should be retired, split into Chuanqiandian Cluster Miao, Small Flowery Miao, Horned Miao and Hmong Njua. Until now Hmong Njua [blu] as described in the Ethnologue 15th ed. was awkwardly forced to encompass a large number of Chuanqiandian Miao lects. The specific variety Hmong Njua (or Hmongb Nzhuab), appearing under country headings for Thailand, Vietnam, Laos and Myanmar and also spoken by many overseas Hmong around the world, is one member of the Chuanqiandian Cluster Miao group. Thus Hmong Njua has been used in two senses until now, denoting a broad category of several dozen Chuanqiandian lects, and in a much narrower sense, denoting one specific variety within that broad category. Because from now on it would be unclear in any given use of the identifier as to whether [blu] meant the old, overly broad Hmong Njua, or the new, more proper Hmong Njua, the identifier [blu] must be retired from use. The specific variety Hmong Njua should be given a new identifier to remove that ambiguity, and the broad category of Chuanqiandian lects should be split into four new entries.
Chinese linguists normally organize the broad category of Chuanqiandian lects, formerly represented in the Ethnologue by the lect best known overseas, Hmong Njua, into three or four clusters of closely related lects. They call these three clusters 川黔滇方言川黔滇次方 言第一、第二、第三、第四个土语. In English these could be translated as the first, second, third and fourth local dialects of the Chuanqiandian sub-dialect of the Chuanqiandian dialect of the Miao language.
Chinese linguists have arranged these multiple varieties in three or four groups based on closeness of genetic relationship, determined through analysis of extensive word lists, and on estimates of inherent intelligibility, gained through observations of ability to communicate across lects in the mother tongue.
While the many lects within the Chuanqiandian Cluster Miao group (corresponding to the first local dialect described by Chinese linguists) do differ somewhat in phonology and lexicon, and their speakers have autonyms, clothing and customs distinct from other subgroups within the cluster, and while marriage tends to be within the same subgroup, there is fairly good inherent intelligibility at a functional level across lects within the cluster.
Small Flowery Miao or Gha-Mu, corresponding to the second local dialect described by Chinese linguists, is a distinct ethnolinguistic subgroup with its own clear identity. Through historical reconstruction Chinese linguists have determined that the Small Flowery Miao lect is closely related to other lects within the Chuanqiandian sub-dialect, and they state that there is partial intelligibility between this lect and Chuanqiandian Cluster Miao (the first local dialect).
Sinicized Miao or Hmong Sa, posited by at least one Chinese linguist (Li Yunbing) as a fourth local dialect of the Chuanqiandian sub-dialect, is also a distinct ethnolinguistic sub- group, and is phonologically more divergent from the Chuanqiandian Cluster Miao lects (the first local dialect) than Small Flowery Miao is from the Chuanqiandian Cluster Miao lects. There is marginal intelligibility between Sinicized Miao and either Chuanqiandian Cluster Miao lects or Small Flowery Miao. It is believed, however, that this is the same language that is already represented by the code [hmz] Hmong Shua, previously identified as only being used in Vietnam. Thus, this proposal recommends an expansion of the denotation of [hmz] Hmong Shua to incorporate this lect as spoken in China (cf change request 2007-132)
Horned Miao, although it has been classified in several different ways by Chinese linguists, is also a distinct ethnolinguistic sub-group speaking a variety of Miao that is phonologically divergent from other lects in the Chuanqiandian sub-dialect and only partially intelligible with them.
The specific variety Hmong Njua (or Hmongb Nzhuab), spoken in China, Thailand, Vietnam, Laos, Myanmar and by many overseas Hmong around the world, is one member of the Chuanqiandian Cluster Miao group. A significant body of literature now exists in Hmong Njua in the RPA writing system used since the 1950's in Laos, Thailand and in western countries where overseas Hmong live. Speakers of the Hmong Njua lect, along with speakers of Hmong Daw, are probably the best-known members outside of China of this large over-arching ethnolinguistic group known as Miao or Hmong.