What is a reason for perfecting a claim for priority date in a Reissue Application?

Perfecting a claim for priority date in a Reissue Application is primarily important for correcting references. In the context of patent law, a reissue application is filed to fix errors in an already granted patent. One common reason for such corrections is to ensure that the priority date, which is critical for determining the novelty and non-obviousness of the invention, is maintained.

When the reference to prior art or the scope of allowable claims might have been improperly handled or documented, perfecting the claim can enhance the legal standing of the application by aligning it with earlier filed applications. This can significantly affect the outcome of patentability assessments and potential infringement matters, ensuring that the patent owner is protected against references that might invalidate their claims.

In this case, while examining the other options, expanding the patent term, supporting new inventions, and reducing filing costs do not directly relate to the essence of perfecting a claim for priority date. The focus on correcting references underscores the need to maintain accuracy concerning the patent's historical context and its legal protections.