Kin Groups and Descent. Mailu clans are patrilineal, dispersed over several villages. Local (village-level) clan "sections" are named, exogamous, and agnatically recruited. An in-marrying woman exchanges her clan membership for that of her husband, and her children, though initially held to belong to her brother (thus to her father's lineage), are normally claimed at some point by her husband through the gift of a pig. It is not unusual, however, for a childless man to adopt one of his sister's sons.
Kinship Terminology. Mailu employ a system of classificatory terms for all relatives of previous generations (i.e., grandparents, parents, uncles, and aunts) in order to get around the taboo of using personal names when speaking of or directly addressing these relatives. These terms mark not only one's genealogical position but also differentiate Between elder and younger members of a single generation. However, while several different relations may be designated by a single term (e.g., a man's elder brother, his father's elder brother's son, and his mother's sister's elder son may all be referred to by the term uiniegi), other terms or qualifiers are used to mark more specifically the actual relationship of the relative when necessary.