A service mark is a registered mark used to identify a service. Like a trademark, a service mark grants the holder the right to exclude others from using the mark in commerce. The underlying policy objective of allowing for registration of marks and exclusion of others from use is to allow companies to offer services and products to the public under a specific mark without the risk that other companies may try to use the mark as well to confuse consumers and corrupt goodwill a company may have built around its brand. A company can apply for a service mark through the U.S. Patent and Trademark Office. Service marks have laxer standards for the use in commerce requirement compared to trademarks. Service marks, like trademarks, must meet rigorous distinctiveness requirements in order to be registered. Trademarks are designated by the inclusion of the TM symbol, while service marks are designed by a symbol of an R within a circle. Service marks differ from trademarks in that service marks are usually contained in advertising materials for the service while a trademark shows up on product packaging. As a service has no package to mark, the service mark must instead be contained in advertising materials. Sounds can be registered as service marks.