A patent caveat no longer exists. It was a form of legal document that could be filed with the patent office of the USA. Patent caveats were in use from 1836 to 1909 when such were discontinued. It was similar to a patent application and also included elements such drawings and descriptions. The caveat, however, did not include any claims which one finds in the normal patent application. The caveat was rather a legal notice of the intention to apply for a patent at a later stage. One would have 12 months in which to then file the patent application. If one paid the renewal fee after a year the patent caveat could renewed for a like period.
Why Use it?
With the fees being far lower than the actual patent application filing fees, one could save a lot of money while exploring the marketability of the invention. With no attorney fees involved in the application, the applicant could relatively easy reserve a patent and thus limit possibilities of competitors registering patents for the period. The provisional patent application of today is the modern equivalent of the patent caveat. The difference lies in the renewable nature of the patent caveat as the provisional patent cannot be renewed whereas the patent caveat can. In previous years when caveats were still in force one would file the caveat to prevent others from registering a similar patent for a related invention before the final application was done. The procedure involved a search of the caveat lists to determine that no other caveats were registered prior to the particular caveat application date. If such wee found, the applicant would receive a notification from the relevant Patent Office about the invention. The applicant then had a window of opportunity which lasted three months to file the final patent application which had to be accompanied by the claims for the invention.