A reissue will not be granted to "recapture" claimed subject matter which was surrendered in an application to obtain the original patent. This section covers the three-step test for recapture:

(1) first, we determine whether, and in what respect, the reissue claims are broader in scope than the original patent claims;

(2) next, we determine whether the broader aspects of the reissue claims relate to subject matter surrendered in the original prosecution; and

(3) finally, we determine whether the reissue claims were materially narrowed in other respects, so that the claims may not have been enlarged, and hence avoid the recapture rule.

• Review Ed9 10.2019: 1412.02

This section discusses Certificates of correction when the Office made the mistake. Certificates of correction are used for minor mistakes (like typos) in issued patents. It includes additional information on when to use a Certificate of correction.

• Review Ed9 10.2019: 1480

This section discusses Certificates of correction which were not the fault of the Office. It covers the two separate statutory requirements that must be made before a Certificate of correction for an applicant's mistake may issue.

• Review Ed9 10.2019: 1481