A more thorough explanation:

The recapture rule is a doctrine in patent law that states a patent holder cannot regain a claim that they previously abandoned in order to get their patent approved. This means that if a patent holder gave up a claim to get their patent approved, they cannot later try to regain that claim through a reissue patent.

For example, if a patent holder originally filed a patent application with ten claims, but during the approval process, they abandoned one of those claims to get the patent approved, they cannot later try to regain that abandoned claim through a reissue patent.

The recapture rule is in place to prevent patent holders from strategically abandoning claims during the approval process and then trying to regain them later through a reissue patent. This would be unfair to competitors who may have relied on the abandoned claim when developing their own products.