15 U.S.C. § 1063: Opposition to registration

Any person who believes that he would be damaged by the registration of a mark upon the principal register, including the registration of any mark which would be likely to cause dilution by blurring or dilution by tarnishment under section 1125(c) of this title , may, upon payment of the prescribed fee, file an opposition in the Patent and Trademark Office, stating the grounds therefor, within thirty days after the publication under subsection (a) of section 1062 of this title of the mark sought to be registered. Upon written request prior to the expiration of the thirty-day period, the time for filing opposition shall be extended for an additional thirty days, and further extensions of time for filing opposition may be granted by the Director for good cause when requested prior to the expiration of an extension. The Director shall notify the applicant of each extension of the time for filing opposition. An opposition may be amended under such conditions as may be prescribed by the Director. a mark entitled to registration on the principal register based on an application filed under section 1051(a) of this title or pursuant to section 1126 of this title shall be registered in the Patent and Trademark Office, a certificate of registration shall be issued, and notice of the registration shall be published in the Official Gazette of the Patent and Trademark Office; or a notice of allowance shall be issued to the applicant if the applicant applied for registration under section 1051(b) of this title .