Duty of disclosure
In U.S. legal procedure, each party to a lawsuit has the duty to disclose certain information, such as the names and addresses of witnesses, and copies of any documents that it intends to use as evidence, to the opposing party. This duty is subject to certain exceptions, as outlined in the Federal Rules of Civil Procedure; furthermore, the rules applicable in state courts vary from state to state.
In United States patent law, during patent prosecution, an applicant has a duty to disclose all information material to patentability. Breach of this duty can lead to a holding of inequitable conduct, in which case the patent is unenforceable.
