A reissue patent application is filed to correct mistakes in the issued patent. Such “reissue applications” must typically be filed within a particular period of time following issuance of the original patent. In the United States, the patent holder may even seek to broaden the scope of the invention defined in the claims by filing a reissue application, although a broadening reissue in the USA must be filed within 2 years from grant. Also, in the United States, only the patent holder may file for reissue.