What are the special considerations for amending a reissue application with prior changes?

This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.

When amending a reissue application where the patent has undergone prior changes:

• For a previously reissued patent: Use double underlining and double bracketing to show changes relative to the first reissue
• For a patent with a certificate of correction: Present the amendment as if changes from the certificate are part of the original patent
• For a patent with a statutory disclaimer: Delete disclaimed claims by lining through, not with brackets

The MPEP provides specific guidance: “As per MPEP § 1411, double underlining and double bracketing are used in the second reissue application to show amendments made relative to the first reissue patent.” For certificates of correction: “An amendment in the reissue application must be presented as if the changes made to the original patent text via the certificate of correction are a part of the original patent.” And for statutory disclaimers: “Any claim statutorily disclaimed is no longer in the patent, and such a claim cannot be amended. A disclaimed claim must be deleted by a direction to strike through the claim, i.e., the statutorily disclaimed claim(s) should be lined through, and not surrounded by brackets.“