Yaka community leaders have a number of items that form part of their royal collection. One of these items is the kopa ceremonial cup (also called koopa or mbassa; used by the Suku too). Presented to every new chief at his initiation, kopa cups are traditionally used to drink palm wine during ritual ceremonies to demonstrate authority and power. During a chief's reign, no one else is allowed to touch the kopa without authority from the chief himself. At the death of the chief, the kopa is passed down to his successor who must recite the names of previous owners of the cup.