What is a substitute specification?

A substitute specification is a rewritten version of the original specification that may be required during the prosecution of a patent application. This typically occurs when the original specification does not sufficiently describe the invention or fails to meet the necessary legal requirements. A substitute specification allows the inventor or applicant to clarify, correct, or expand upon the original disclosure to ensure that it adequately supports the claims made in the application.

In patent practice, it's crucial that the specification is clear and complete, as it serves to provide the legal foundation for the claims. By allowing for revisions or clarifications through a substitute specification, the patent process can proceed more effectively and help address any issues raised by the patent examiner regarding the adequacy of the initial filing.

The other options, while related to larger concepts within patent application practices, do not accurately define a substitute specification. For instance, a full application amendment or a new claim set does not specifically refer to the rewritten context of the entire specification. Similarly, a substitute application for missing pages pertains to a different issue, primarily how to handle incomplete submissions rather than revising the specification itself.