On March 7, 1912, the Commissioner of Patents decided in Ex parte Bayles, 176 O.G. 749 that “[u]ntil a[n] [reissue] application is ended in all its divisions the vitality of the original patent continues so far as required to support that portion of the [reissue] application which remains undecided.” This would be true even if the parent reissue patent were to issue during the pendency of the divisional application. On August 31, 1911, the petitioner in Bayles filed a reissue application containing both method and apparatus claims found in the original patent. Subsequently, by amendment, the petitioner canceled the method claims for the purpose of filing a divisional reissue application. The divisional reissue application claiming the method was filed prior to issuance of the parent reissue application claiming the apparatus. The Commissioner relied on the August 31, 1880 decision of the Acting Attorney-General in the case of ex parte Greaves (C.D., 1880, 213; 18 O.G., 623; 16 Op. Atty. Gen., 560) holding that the good sense of the maxim pendente lite nihil innovator applied. The purported surrender of the original patent when the parent reissue patent issued after the filing of the divisional reissue application did not prevent a division of the reissue from issuing. In MPEP § 1451 (II) states that “[t]he decision of In re Graff, 111 F.3d 874, 42 USPQ2d 1471 (Fed. Cir. 1997) interprets 35 U.S.C. 251 to permit multiple reissue patents to issue even where the multiple reissue patents are not for “distinct and separate parts of the thing patented.” This section further cautions that “[a]s is true for the case of multiple divisional reissue applications, all of the claims of the patent to be reissued must be presented in both the parent reissue application and the continuation reissue application in some form, i.e., as amended, as unamended, or as canceled. The same claim of the patent cannot, however be presented for examination in both the parent reissue application and the continuation reissue application, as a pending claim, in either its original or amended versions. …Where the parent reissue application issues **>before< the examination of the continuation >reissue application<, the claims of the continuation >reissue application< should be carefully reviewed for double patenting over the claims of the parent >reissue application<. Where the parent and the continuation reissue applications are examined together, a provisional double patenting rejection should be made in both cases as to any overlapping claims. See MPEP § 804 – § 804.04 as to double patenting rejections. Any terminal disclaimer filed to obviate an obviousness-type double patenting rejection ensures common ownership of the reissue patents throughout the remainder of the unexpired term of the original patent.” However, the MPEP is silent as to the effect of the language of 35 U.S.C. § 252 which indicates that “[t]he surrender of the original patent shall take effect upon the issue of the reissued patent, and every reissued patent shall have the same effect and operation in law, on the trial of actions for causes thereafter arising, as if the same had been originally granted in such amended form, but in so far as the claims of the original and reissued patents are substantially identical, such surrender shall not affect any action then pending nor abate any cause of action then existing, and the reissued patent, to the extent that its claims are substantially identical with the original patent, shall constitute a continuation thereof and have effect continuously from the date of the original patent.” Do the principles announced in ex parte Bayles apply? Namely, because a continuation reissue was filed prior to issuance of the parent reissue patent does surrender of the original patent not take place until issuance of the last continuation reissue patent? Suppose that the original patent claimed an invention AB. Within two years of the grant of the original patent a broadened reissue application was filed claiming the invention as AB, AbrBsp and AspBsp. During examination applicant facing a rejection of claims to AB, and AbrBsp, chooses to file a continuation reissue as to these claims, while thereafter letting the parent reissue application claiming only AspBsp issue. Putting aside the obviousness-type double patenting issue that can be obviated by filing a terminal disclaimer in the continuation reissue application, what effect, if any, does section 252 have on the examination of claims AB in the continuation reissue application. Are claims to AB surrendered by operation of section 252 or do the Bayles principles apply to avoid the surrender of original patent claims to AB? We are unaware of any Federal Circuit precedent directly on point. We leave it to you to decide.