Forward citation

Cross-referenced

Backward citation

An earlier patent or publication that a given patent cites as part of its prior-art foundation — listed on the patent's front page as "references cited." Backward citations show what an invention built upon: a drone patent might cite earlier flight-control patents. Some references come from the applicant, others are added by the examiner during the prior-art search. The opposite of a forward citation.

Cross-referenced

Patent

A government-granted right that gives an inventor the exclusive right to prevent others from making, using, selling, or importing a patented invention within the country that granted the patent, for a limited time. A patent does not give the owner the right to practice the invention — only the right to exclude others. The US issues three types: utility, design, and plant patents.

Cross-referenced

Prior art

All publicly available information that existed before a patent's priority date that is relevant to the novelty and non-obviousness of the claimed invention. Prior art includes earlier patents, published patent applications, journal articles, product manuals, conference presentations, and anything that was publicly known or in use. Searching prior art before filing is one of the most valuable steps an inventor can take.

First-to-file

The rule, adopted in the U.S. by the America Invents Act, that when two people independently invent the same thing the patent goes to whoever filed first, not whoever invented first. It makes the filing date critical.

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.

Freedom to operate (FTO)

A legal opinion assessing whether a product, process, or service can be commercialized without infringing any valid, in-force patents held by others. FTO searches are typically conducted before launching a product. An FTO opinion does not guarantee safety from infringement claims, but a good-faith, well-documented FTO analysis can reduce willfulness damages if litigation occurs.