Applicants and agents appearing before the Patent Office are obligated by a duty of candor and disclosure to the Office. This means, when you file a patent application, you must continually update the contents of that application with anything that may be or become relevant to patentability. This most frequently arises in the form of submitting Information Disclosure Statement, or an IDS. An IDS is often submitted with the initial filing of an application; it will disclose a list of patents, patent application publications, foreign references, and non-patent literature that the applicant was aware of before filing, usually either because of a patentability search, pre-filing due diligence, or knowledge and experience in the industry. However, the duty to disclose relevant prior art continues during prosecution, and applicants will generally disclose prior art that surfaces. Failing to disclose does expose a patent that eventually issues from the application to the risk of invalidation.
IDSs submitted during prosecution are often spurred by parallel foreign prosecution. Because the US Patent Office can be quite slow in prosecution, foreign offices frequently will produce relevant prior art before the US. If a PCT application is filed, the International Searching Authority will usually provide its search report before the US Patent Office has begun examination. The results of such a search report should be disclosed in the US. Some foreign offices move very quickly, and examination results there should also be disclosed. This disclosure duty is not limited to prior art revealed before US examination; it continues throughout prosecution. And there are timing requirements for disclosure. The results of foreign offices should be disclosed within 3 months of production.