GENERAL INFORMATION AND CORRESPONDENCE

All business with the Patent and Trademark Office should be transacted by writing to "COMMISSIONER OF PATENTS AND TRADEMARKS, WASHINGTON, D. C. 20231." Correspondents should be sure to include their full return addresses, including Zip Codes.
The principal location of the office is Crystal Plaza 3, 2021 Jefferson Davis Highway, Arlington, Virginia. The personal attendance of applicants at the Office is unnecessary.
Applicants and attorneys are required to conduct their business with decorum and courtesy. Papers presented in violation of this requirement will be returned.
Separate letters (but not necessarily in separate envelopes) should be written in relation to each distinct subject of inquiry, such as assignments, payments, orders for printed copies of patents, orders for copies of records, requests for other services, etc. None of these should be included with letters responding to Office actions in applications.
When a letter concerns a patent application, the correspondent must include the serial number, filing date and Group Art Unit number. When a letter concerns a patent, it must include the name of the patentee, the title of the invention, the patent number and the date of issue.
An order for a copy of an assignment must give the book and page or reel and frame of the record, as well as the name of the inventor; otherwise, an additional charge is made for the time consumed in making the search for the assignment.
Applications for patents are not open to the public, and no information concerning them is released except on written authority of the applicant, his assignee, or his attorney, or when necessary to the conduct of the business of the Office. Patents and related records, including records of any decisions, the records of assignments other than those relating to assignments of patent applications, books, and other records and papers in the Office are open to the public. They may be inspected in the Patent and Trademark Office Search Room or copies may be ordered.
The Office cannot respond to inquiries concerning the novelty and patentability of an invention in advance of the filing of an application; give advice as to possible infringement of a patent; advise of the propriety of filing an application; respond to inquiries as to whether or to whom any alleged invention has been patented; act as an expounder of the patent law or as counselor for individuals, except in deciding questions arising before it in regularly filed cases. Information of a general nature may be furnished either directly or by supplying or calling attention to an appropriate publication.