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Written description

Definition

A requirement under 35 USC § 112 that an inventorinventorThe person who actually conceived the invention. Listed on the patent regardless of who owns it.Read more → must demonstrate, through the specificationspecificationThe main body of the patent — describes the invention in detail. Used to interpret the claims.Read more →, that they actually possessed the claimed invention at the time of filing — not just that they had a vague idea. Written descriptionwritten description112 requirement: the inventor must show they actually possessed the claimed invention at filing — not just had a vague idea.Read more → is separate from enablementenablement112 requirement: the patent must teach a skilled person to make and use the invention without undue experimentation. Broad claims can fail enablement.Read more →: enablement asks whether the reader can make the invention; written description asks whether the inventor had already conceived it. Failing the written description requirement is common when inventors try to add new matter to a continuationcontinuationA new patent application that claims priority to an earlier still-pending parent application.Read more →.

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Specification

The written description portion of a patent application — everything except the claims. The specification must describe the invention in enough detail that someone skilled in the field could make and use it. It typically includes background of the invention, a summary, a description of the drawings, and a detailed description of at least one embodiment. Courts use the specification to interpret what claim terms mean.

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Continuation

A new patent application filed while a parent application is still pending, using the same specification but with different (usually narrower or broader) claims. Continuations allow inventors to pursue multiple rounds of claims from one original disclosure. Many technology companies maintain families of ten or more continuations from a single core invention, each covering a different aspect.

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Enablement

A requirement under 35 USC § 112 that a patent's specification must teach someone skilled in the relevant field how to make and use the invention — without undue experimentation. If the specification fails to enable the full scope of what the claims cover, the patent is invalid for lack of enablement. This is one of the most frequent grounds for invalidating broad software and biotechnology patents.

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Inventor

The person (or persons) who conceived the claimed invention. Inventorship is a legal concept distinct from contribution to a project — someone who merely built what was designed, or who had a general idea that was made more specific by someone else, may not qualify as an inventor. Incorrectly listing inventors can invalidate a patent.

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Post-grant review (PGR)

A USPTO proceeding to challenge a recently granted patent, within nine months of grant, on almost any ground of invalidity — including eligibility and written description. It is broader than inter partes review, which is narrower and becomes available later.

Willful infringement

Infringement carried out with knowledge of the patent and reckless disregard for it. A finding of willfulness lets a court increase damages up to three times (enhanced damages), so accused companies often seek an opinion of counsel to guard against it.

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