A study explored, from a sociolinguistic perspective, the phenomenon of indoubill, patterns and usage of a special variety of Lingala, among a group of delinquent urban youth in Kinshasa (Zaire). It is proposed that: (1) at a particular moment in its social history, the community experienced sociocultural change that brought with it a special language variety replacing particular functions in the communicative strategies of the standard language; (2) certain social and behavioral characteristics are reflected in the language variety chosen; (3) the speakers of such a variety can upset the community's lexical repertoire and expression of cultural knowledge; and (4) it is possible to see conflicting relationships among the different varieties evolving. The report begins with an overview of the linguistic situation of Zaire and of Kinshasa, particularly in public administration, justice, the army, the media, and education, and the colonial and post-colonial ideology. The report proceeds to describe the indoubill community, the origins and development of the language variety, monolingual and bilingual constructions, variations in form and spelling, variations in meaning, and borrowing. A variety of social and linguistic hierarchies are examined. Communicative strategies and spoken indoubill are also analyzed. A 96-item bibliography is included. (MSE)