37 C.F.R. § 5.14
(c) Where the application to be filed or exported abroad contains matter not disclosed in the United States application or applications, including the case where the combining of two or more United States applications introduces subject matter not disclosed in any of them, a copy of the application as it is to be filed or exported abroad, must be furnished with the petition. If, however, all new matter in the application to be filed or exported is readily identifiable, the new matter may be submitted in detail and the remainder by reference to the pertinent United States application or applications.
(Pub. L. 94-131, 89 Stat. 685)
[43 FR 20471, May 11, 1978, as amended at 49 FR 13462, Apr. 4, 1984; 62 FR 53204, Oct. 10, 1997; 80 FR 17970, Apr. 2, 2015]