Trademark rights arise from the actual use of the mark. If a product is sold under a brand name, common law trademark rights have been created. Common law trademark rights are developed through use and are not governed by statute. Common law rights have developed under a judicially created scheme of rights governed by state law. Common law trademark rights are limited to the geographic area in which the mark is used. There is no registration requirement to establish common law rights to a trademark, which makes it very difficult to discover whether anyone has trademark rights in a particular mark. Even so an attempt must be made to discover these common law rights.