The Detroit Public Library is a Patent and Trademark Resource Center (PTRC),
supported by the United States Patent and Trademark Office (USPTO). Specialized reference services relating to patents, trademarks and copyright are provided by highly trained and knowledgeable librarians. In addition, the Library's business section is of great help for those who seek to market their inventions, products or services. All services are free and available to the public. Book and material checkout, however, is subject to DPL circulation rules.