What characterizes a 102(g) rejection?

A 102(g) rejection is characterized by the requirement to prove that an inventor was the first to conceive of the invention and that they exercised due diligence in reducing it to practice. This standard emphasizes the importance of the inventor's actions leading to the creation of the invention, often involving an understanding that even if another person files a patent application later, the first inventor may still have rights if they can substantiate their prior conception and diligent actions toward bringing the invention to fruition.

In the context of patent law, such a rejection is rooted in the philosophy that the first person to invent has priority over rights to the invention, as opposed to merely the first to file. This addresses the common misconception that patents are solely determined by filing dates.

The other options detail aspects relevant to other types of rejections or scenarios but do not accurately describe the essence of a 102(g) rejection. Prior art publications relate to different types of patentability inquiries, while foreign patent agreements and publication dates preceding the filing date are pertinent to 102(a) or 102(b) rejections regarding novelty and public disclosure rather than to the priority of invention.