In most of the United States, speed limit signs bear the words "SPEED LIMIT" above the numeric speed limit, as specified in the MUTCD. However, in Alaska and California, speed limits are often labeled "MAXIMUM SPEED" instead. In Oregon, most speed limit signs are simply labeled "SPEED". Canada has similar signs bearing the legend "MAXIMUM", which has a similar meaning in English and French, the country's two main languages. Signs in Australia, Mexico, Panama, and Peru are rectangular but inscribe the numeric limit within a red circle like on Vienna Convention signs. The MUTCD formerly specified an optional metric design that included the words "SPEED LIMIT" and the numeric limit inscribed within a black circle, though it was rarely used in the United States; this design is still occasionally found in Liberia.