Trademarks approved and registered by the Trademark Office are registered trademarks, including commodity trademarks, service trademarks, collective trademarks and certification trademarks. Commodity trademarks are trademarks used on commodities, which are relative to service trademarks. A service sign refers to a sign that someone uses to distinguish his service from others' when providing services or in advertisements. A collective trademark refers to a sign registered in the name of a group, association or other organization and used by members of the organization in commercial activities to show the membership of users in the organization. A certification trademark refers to a mark controlled by an organization that has the ability to supervise a commodity or service and used by units or individuals outside the organization to prove the origin, raw materials, manufacturing methods, quality or other specific qualities of the commodity or service.