Question:
If additional defects or errors are corrected in the reissue after the filing of the reissue oath or declaration, is a supplemental reissue oath or declaration required?
Answer:
For applications filed on or after September 16, 2012, if additional defects or errors are corrected in the reissue after the filing of the reissue oath or declaration, a supplemental reissue oath or declaration is not required.
However, where all errors previously identified in the reissue oath/declaration are no longer being relied upon as the basis for reissue, the applicant must explicitly identify on the record an error being relied upon as the basis for reissue (e.g., in the remarks accompanying an amendment). Identification of the error must be conspicuous and clear, and must comply with 35 U.S.C. 251.
If the reissue application was filed before September 16, 2012 and the amendment corrects an “error” under 35 U.S.C. 251, then a supplemental oath or declaration will be required. The examiner should telephone applicant and request the supplemental oath or declaration, which must be filed before the application can be counted as an allowance.
Chapter Details:
The answer to this question can be found in chapter 1400 of the MPEP. This chapter covers Correction of Patents.
The answer is from the 9th Edition, Revision 07.2022, Published February 2023. Depending on future changes to the MPEP, the question and answer may or may not be applicable in later Editions or revisions.
Section Summary:
This question and answer comes from section 1455 of the MPEP.  The following is a brief summary of section 1455.
1455 Allowance and Issue
This section covers allowance and issue including changes to the original patent and claim numbering. Renumbering of the original patent claims is never permitted. In addition, at least one claim of an allowable reissue application must be designated for printing in the Official Gazette.
This section also discusses parent application data on the bibliographic data sheet of the original patent file and examiner’s amendments and it briefly touches on reissue oaths or declarations.