A cancellation proceeding is an administrative proceeding before the USPTO’s Trademark Trial and Appeal Board (TTAB) where one party tries to cancel the registered trademark of another. An opposition proceeding is when one party opposes the registration of another party’s trademark during the opposition period, before the mark is registered. Either proceeding can be initiated by any party who believes it will be damaged by the registration of the mark.
Cancellation and opposition proceedings take place before the TTAB. Both proceedings are similar to civil litigation proceedings but TTAB proceedings are only limited to determining whether or not a mark can be registered. Non-trademark claims cannot be decided by the TTAB.