Freedom to operate (FTO)

File wrapper

The complete record of all communications between an applicant and the USPTO during patent prosecution — including the original application, all office actions, all responses, and the notice of allowance. Also called the "prosecution history." The file wrapper is public and permanent; courts use it during litigation to interpret the scope of claims based on statements the applicant made to the examiner.

Abstract

A brief summary (300 words or fewer) that appears at the top of every patent. The abstract describes what the invention does in general terms. Legally, it has almost no weight — courts use the claims to determine what a patent covers, not the abstract. The abstract is useful mainly for quickly scanning patents during a prior art search.

Anticipation

A legal standard for rejecting a patent claim. If every element of a claim was already disclosed in a single prior art reference — in a patent, article, or product — the claim is "anticipated" and cannot be patented. Anticipation requires a single source to contain every element; if you need two sources, it's an obviousness argument, not anticipation.

Appeal

A request to have a patent examiner's rejection reviewed by a higher authority. After receiving multiple rejections, an applicant can appeal to the Patent Trial and Appeal Board (PTAB) within the USPTO, and from there to federal court. Appeals are expensive and slow, but sometimes necessary when an examiner applies the law incorrectly.

Art unit

A group of patent examiners at the USPTO who specialize in a particular technology area. Each application is assigned to the art unit whose examiners are trained in the relevant field. The art unit assignment matters because examiner expertise — and rejection rates — vary significantly across technology areas.

Assignee

The legal owner of a patent, who may or may not be the inventor. When an employee invents something in the course of their employment, most companies require inventors to assign patent rights to the employer. The assignee appears on the patent document and has the right to license or enforce the patent.