When meeting with inventors, one question that they often ask is "what will I have to disclose to the Patent Office?" This type of disclosure is not what is required for describing an invention in a patent application. It is often ignored until later stages of the examination of a US patent application, but it can be critical even at the initial stages of preparing a patent application. What does "Disclosure” mean?? Under US patent law, all information in the possession of the inventor, applicant and their representatives that is "material to patentability" must be disclosed to the US Patent Office (USPTO). Material to patentability means that the information might affect the patentability of a claimed invention. All information!? What information has to be disclosed? When does this information need to be disclosed to the USPTO? Honesty is the Best and Only Policy! As a final note, always remember that honesty is the best and only policy for avoiding running afoul of the disclosure requirement and for avoiding problems related to this issue during future litigation.