Lof (Spanish: levo and lov) or caví (Spanish: Cahuín); formed the basic social organization of the Mapuche, Huilliche and the extinct Picunche peoples, consisting of a familial clan or lineage that recognizes the authority of a lonco (cacique). The Lof or caví is formed by diverse families that share the same territory and they are considered mutually related, descended from a common ancestor. Several lof form a rehue, and nine rehue formed the aillarehue, that formed one of the 3 or 5 great territorial confederations of the Mapuches, the Butalmapu (great earth).
The identity of lof was reinforced by the accomplishment of diverse community and festive activities. Lof habitually shared a unique rehue, or Machi's altar, in which the more significant religious ceremonies were performed. On the other hand the vitality of the clan shone in the accomplishment of lof kudau, a species of retributive communitarian work followed by a celebration with a feast and drinking, similar to the mingaco of the quechuas. Lof kudau consisted usually of harvests, and other work that demanded large amounts of manpower, mainly in the fields of rich and prestigious personages of the lof: the ulmenes and loncos, who could afford to provide enough food and drink.