U.S. registrations may be renewed indefinitely for successive ten year terms. Just as registrations must be maintained, through affidavits, fees, and renewal applications, marks must be maintained, through proper use and due diligence. Generic terms designate a type of product or service, without calling to mind any specific manufacturer or provider. A generic term cannot be a mark. Generic terms are in the public domain, and may be used freely by anyone.
Marks generally lose their source-identifying function through abandonment .
Intentional abandonment occurs when an owner fails to use a mark for a specified period, and does not intend to resume use. Marks also may be abandoned unintentionally, through improper use. Thus, marks should be used consistently, and distinctively, to enhance their source-identifying function. If an entity other than the trademark owner, uses a mark on its own products, in its own way, the mark's ability to function as an indicator of source is diminished. For this reason, all third-party uses of a mark should be licensed, and monitored carefully.