What happens if the best mode is not disclosed before the filing of a patent application?

The concept of the best mode is fundamental to U.S. patent law, as it mandates that the patent applicant disclose the best way they know of carrying out their invention at the time of filing. However, failure to disclose the best mode does not inherently invalidate the patent application or prevent it from claiming priority from another application.

Choosing the priority claim indicates that even if the best mode is not disclosed, the application can still benefit from an earlier filing date of a related application, as long as that earlier application contains the required disclosures. This means that the newer application can derive its legal standing from that priority application, which could strengthen its position in terms of patentability, assuming other patentability requirements are met.

The assertion that a patent application is automatically invalid without the best mode disclosure or that it will never be granted overlooks the fact that the failure to disclose the best mode is not treated as a ground for automatic invalidity. Moreover, the ability to reissue a patent has specific requirements and conditions and does not serve as a means to retroactively cure a best mode deficiency.

Overall, understanding the implications of the best mode requirement is important, but it does not preclude the potential for claiming priority or securing a patent under certain circumstances if other criteria are fulfilled.