Ugg boots are a unisex style of sheepskin boot originating in Australia. The boots are typically made of twin-faced sheepskin with fleece on the inside, a tanned outer surface and a synthetic sole. The term "ugg boots" originated in Australia, initially for utilitarian footwear worn for warmth, and which were often worn by surfers during the 1960s. In the 1970s, the boots were introduced to the surf culture of the United Kingdom and the United States. Sheepskin boots became a fashion trend in the U.S. in the late 1990s and a worldwide trend in the mid-2000s. In Australia, they are worn predominantly as slippers and often associated with daggy fashion sense and bogan culture. Prior legal disputes between some manufacturers of sheepskin boots arose as to distinguish whether "ugg" is a protected trademark, or a generic term and thus ineligible for trademark protection. There are more than 70 registered trademarks that include the term "ugg" in various logos and designs in Australia and New Zealand, as the term is considered a generic reference to a type of shoe. Outside Australia and New Zealand, UGG is a brand manufactured by the California-based Deckers Outdoor Corporation, with most of its manufacturing based in China and with registered trademarks in over 130 countries worldwide including the US, UK, Canada, all European Union members, and China. Despite the difference in capitalisation and pronunciation, Deckers Corporation actively asserts its "UGG" trade mark () against Australian traders who sell their "ugg boots" overseas. Noteworthy manufacturers in Australia and New Zealand are EMU Australia, Uggs-N-Rugs and Ugg Australia. While Deckers is often referred to as the leading manufacturer of the footwear style outside Australia, Deckers refers to its boots as the "UGG-brand" boot, and associates it with a "California lifestyle". Following an investigation by the Australian Competition & Consumer Commission into allegedly misleading and deceptive use of "Australia" in its branding, Deckers has rebranded from "UGG Australia" to "UGG". History There are different claims to the origins of the ugg boot style. Artisanal sheepskin boots were known in rural Australia during the 1920s, and were reportedly worn by shearers as they found them resistant to wool yolk (lanolin), which would rot their ordinary boots. However, the date of commercial manufacturing began remains unclear. The boots were reportedly being manufactured in 1933 by Blue Mountains Ugg Boots of New South Wales. Frank Mortel of Mortels Sheepskin Factory has