Eastern Cham speakers, as well as being bilingual in Vietnamese, use two varieties of Eastern Cham; a High (H) and a Low (L) variety. These exhibit significant phonological differences. L is used on colloquial contexts, and is not regarded by speakers as having high status. it is not normally written. H mostly exists in written form, as well as being used in religious or formal ceremonies. A large (relative to the size of the community) body of literature exists written in Eastern Cham H, mostly comprised of stone inscriptions, religious texts and epics. Because not all speakers achieve full competence in H, a variety of syntactic and phonological forms have been codified over the years. The Committee for the Standardization of the Cham Script was created in the late 1970s to standardize the script. Since that time, the Committee has proposed a number of changes to Cham orthography, which have met with varying degrees of acceptance.
Diglossia, Bilingualism, and the Revitalization of Written Eastern Cham. Marc Brunelle. University of Ottawa 2008. hosted at http://scholarspace.manoa.hawaii.edu/handle/10125/1848