A Certificate of Correction is requested for which kind of correction?

A Certificate of Correction is specifically designed to address clerical mistakes, such as typographical errors, that do not affect the substantive elements of a patent and are made in the document during the filing process. This allows for the correction of obvious mistakes that can easily be corrected without changing the meaning of the patent claims or the essence of the invention. Such corrections typically include errors in spelling, grammar, or even incorrect reference numerals, which can be fixed to ensure the patent accurately reflects the intended disclosure.

The nature of a Certificate of Correction is administrative, aimed at ensuring that the patent document aligns with what was originally intended without altering the fundamental rights conferred by the patent itself. Other options, such as substantial changes in claims or changes in inventorship, involve more significant legal implications and require different procedures, rather than the straightforward administrative correction covered by a Certificate of Correction. Similarly, patent term extension requests are a separate process entirely, focused on extending the duration of patent protection based on specific criteria. Thus, option B accurately reflects the appropriate use of a Certificate of Correction for clerical mistakes.