What is a "Disclosure Document"?

There are various meanings to a "disclosure document" - one meaning is the invention disclosure that the inventor generates setting forth the details of his invention. Normally he will use this document to draft his patent application if he is going to file his patent application himself. Otherwise, he will provide such document to a patent attorney or agent who will then draft the patent application from such disclosure document. In the current state of patents, this disclosure document does not carry any priority date or value - years ago, when the US was on a "first to invent" basis, the disclosure document could be used to prove or support an invention date prior to the date of actually filing one's patent application - now, since the US is currently on the "first to file" system, the first one to file a patent application is the senior party if rights to a particular invention are disputed.

A second meaning for "disclosure document" is better known as an Information Disclosure Document - when filing a patent application, or having a patent application on file, you are required to disclose to the Patent Office all prior art of which you are aware. Failure to do so can be alleged to be fraud upon the Patent Office - you are not required to go out and search for pertinent prior art, but if you are aware of any relevant prior art, you have a duty to disclose it to the Patent Office - this may come to your knowledge as a result of a patent search having been performed, or as a result of the uncovering of relevant prior art in another country while, for example, a corresponding application is being examined.