A patent agent can only act in a representative capacity in patent matters presented to the USPTO, and may not represent a patent holder or applicant in a court of law. To be eligible for taking the patent bar exam, a candidate must possess a degree in "engineering or physical science or the equivalent of such a degree". Any person who practice trademark law before the USPTO must be an active member in good standing of the highest court of any state. The United States allows any citizen from any country to sit for the patent bar (if he/she has the requisite technical background). Only Canada has a reciprocity agreement with the United States that confers upon a patent agent similar rights. An unrepresented inventor may file a patent application and prosecute it on his or her own behalf ("pro se"). If it appears to a patent examiner that an inventor filing a "pro se" application is not familiar with the proper procedures of the Patent Office, the examiner may suggest that the filing party obtain representation by a registered patent attorney or patent agent. The patent examiner cannot recommend a specific attorney or agent, but the Patent Office does post a list of those who are registered. While the inventor of a relatively simple-to-describe invention may well be able to produce an adequate specification and detailed drawings, there remains language complexity in what is claimed, either in the particular claim language of a utility application, or in the manner in which drawings are presented in a design application. There is also skill required when searching for prior art that is used to support the application and to prevent applying for a patent for something that may be unpatentable. A patent examiner will make special efforts to help "pro se" inventors understand the process but the failure to adequately understand or respond to an Office action from the USPTO can endanger the inventor's rights, and may lead to abandonment of the application. The USPTO accepts patent applications filed in electronic form. Inventors or their patent agents/attorneys can file applications as Adobe PDF documents. Filing fees can be paid by credit card or by a USPTO "deposit account". The USPTO web site provides free electronic copies of issued patents and patent applications as multiple-page TIFF (graphic) documents. The site also provides Boolean search and analysis tools. The USPTO's free distribution service only distributes the patent documents as a set of TIFF files. Numerous free and commercial services provide patent documents in other formats, such as Adobe PDF and CPC. The USPTO has been criticized for granting patents for impossible or absurd, already known, or arguably obvious inventions.