Code of Federal Regulations Title 37. Patents, Trademarks, and Copyrights § 37.7.27 Priority claim of extension of protection for purposes of examination in the Office

(a) The request for extension of protection contains a claim of priority;

(b) The request for extension of protection specifies the filing date, serial number and the country of the application that forms the basis for the claim of priority;  and

(c) The date of the international registration or the date of recording of the subsequent designation at the International Bureau of the request for extension of protection to the United States is not later than six months after the filing date of the application that forms the basis for the claim of priority.