Patent prosecution describes the interaction between applicants and their representatives, and a patent office with regard to a patent, or an application for a patent. Broadly, patent prosecution can be split into pre-grant prosecution, which involves arguing before, and sometimes negotiation with, a patent office for the grant of a patent, and post-grant prosecution, which involves issues such as post-grant amendment and opposition. Patent prosecution is distinct from patent litigation, which describes legal action relating to the infringement of patents. The rules and laws governing patent prosecution are often laid out in manuals released by the Patent Offices of various governments, such as the Manual of Patent Examining Procedure (MPEP) in the United States, or the Manual of Patent Office Practice (MOPOP) in Canada. Pre-grant prosecution Preparation of an application To obtain patent rights for an inventor, the practitioner typically first drafts an application by interviewing the inventor to understand the nature of the invention and help clarify its novel features. Practitioners need to ascertain what is already known to people familiar with the general field of the invention—such already-known material is termed the prior art, and to obtain drawings and written notes regarding the features of the invention and the background. During this initial phase, sometimes termed "patent preparation", the practitioner may also seek to determine precisely who contributed to the making of the invention. An incorrect listing of inventors may incurably invalidate any patent that might result from an application. This determination is particularly important in the United States, but may be considered less important in other jurisdictions. The practitioner may also seek to find out whether any publications, offers for sale, or other such public disclosures of the invention were made. Under the laws or regulations of some jurisdictions, public disclosures or offers to sell an invention prior to filing an application for a patent may prevent the issuance of the patent. In the U.S. these laws are laid out in Title 35 of the United States Code, §102. After drafting an application for patent, complying with any further rules (such as having the inventor or inventors review the application prior to filing), and obtaining the applicant's permission, the practitioner files the patent application with the patent office. Usually, the practitioner seeks to file the application as soon as possible, because in a majority of jurisdictions including Europe and Japan, if two or more applications on the