A 37 CFR 1.131 affidavit is not an acceptable method to overcome a pre-AIA 35 U.S.C. 102(e) rejection in certain circumstances. According to the MPEP: "When the claims of the reference U.S. patent or U.S. patent application publication and the application are directed to the same invention or are obvious variants, an affidavit or declaration under 37 CFR 1.131(a) is not an acceptable method of overcoming the rejection." In such cases, the examiner must determine whether a double patenting rejection or interference is appropriate: If there is a common assignee or inventor between the application and patent, a double patenting rejection must be made. (See MPEP § 804) If there is no common assignee or inventor and the rejection under pre-AIA 35 U.S.C. 102(e) is the only possible rejection, the examiner must determine whether an interference should be declared. (See MPEP Chapter 2300 for more information on interferences) It's important to note that in these situations, alternative approaches to overcome the rejection may be necessary. To learn more: 37 CFR 1.131 affidavit pre-AIA 35 U.S.C. 102(e) rejection double patenting interference same invention