When Awamori is aged for three years or more, it is called kusu (古酒?, "old liquor"). This pronunciation is unique to Awamori and Okinawa; elsewhere in Japan, the word is pronounced "koshu" and refers to aged sake.[3] Legally, in order to earn the designation "kusu", over 50%, the Awamori must be aged for three years. In practice however, the remainder is usually six months old. If a specific age is noted, then all of the contents must be of at least that age. Awamori is aged underground in constant cool temperatures in clay pots or vases. Containers of Awamori can be found in the caves of Okinawa. Before the Battle of Okinawa during World War II, 200- and even 300-year-old kusu existed, but all were lost in the battle. Several attempts are being made to produce these kusu again