What does "double patenting" refer to?

Double patenting refers specifically to the practice that prevents the issuance of two separate patents for the same invention, which is crucial for maintaining the integrity and exclusivity that a patent grants to its inventor. When the same invention is sought to be patented twice by the same inventor or different parties, it can lead to confusion, overlap, and potential infringement issues, undermining the purpose of the patent system, which is to reward inventors with a temporary monopoly on their inventive work.

This doctrine upholds the principle that each unique invention deserves its own protection without allowing for multiple patents to monopolize the same useful idea or innovation. The underlying rationale is to ensure that each patent represents something distinct and novel rather than simply duplicating an existing patent, which could hinder technological advancement and competitive equity in the marketplace.

In contrast, the other choices touch on different concepts, such as international patent filing, patent expiration, and issues related to inventor attribution, none of which address the specific core idea of preventing two patents for the same invention.