ZAI also supports the U.S. Patent and Trademark Office (PTO) Public Search Facility (PSF), which provides public access to patent and trademark information in a variety of formats, including online, microfilm, and print. ZAI is responsible for collection maintenance of paper and microfilm files, accurately shelving, re-shevling, and implementing methods and processes used to file and maintain patent and trademark documents. We also provide general reference desk support and assist PSF users with basic search support.