Confused by the arcane terminology used by patent lawyers, attorneys, agents, examiners and bloggers?  We feel your pain!  So here you will find a list of common patent-related terms with brief explanations of their meaning.

Anticipate, anticipatedSee novelty.


Patent specifications generally conclude with one or more claims which serve to define the scope of the patent monopoly.  More precisely, a patent claim is a definition, in words, of what the patentee considers to be the invention. 

Since an invention is typically a broader concept that any particular commercial product or process, claims are typically written using language that can be somewhat more abstract than ordinary technical writing, which contributes to the common perception that patent documents are difficult to read and comprehend.


A patent specification must describe at least one way of implementing the invention in sufficient detail to enable a person having ordinary skill in the technical field to which the invention relates to put it into practice.

In other words, in exchange for the patent monopoly, the inventor is required to provide a description that teaches others how to put the invention into effect.  Under US law in particular, this is known as the enablement requirement.  The same, or similar, terminology is sometimes used elsewhere, however in most other jurisdictions the equivalent requirement may be imposed by the concepts of sufficiency or support.

See also: sufficiency, support, fair basis, written description, utility.

Fair basis, fairly based

A requirement that claims be fairly based on the description in the patent specification applies in some jurisdictions and performs, at least to some extent, a role similar to that filled by the written description requirement in the US.

Under the fair basis rule, the specification as a whole is required to make the nature of the invention reasonably clear.  The claims will be fairly based on the description if their scope is consistent with the general description of the invention.

Examples of claims that are not fairly based include claims that are much broader in scope than is justified by the extent of the disclosure in the description and (more obviously) claims that relate to something different from the invention described in the specification.

See also: enablement, sufficiency, support, written description, utility.

Inventive step

See obviousness.

Novel, novelty

One of the criteria for an invention to be patentable is that it must be new. It is more common to refer to this newness requirement as novelty, or we say that the invention must be novel.

The concept of novelty in patent law is generally a narrow one. It is necessary to look to each claim of the patent specification, and compare the set of features defined in the claim with each individual prior art disclosure.  If there is no single disclosure within the prior art that falls wholly within the scope of the claim (ie if exactly the same "invention" does not already exist), then the claim is novel.

A claim is sometimes said to be anticipated by prior art that deprives it of novelty.
See also: obviousness.

Obvious, obviousness

To be granted a patent, it is generally a requirement that an invention not only be novel, but that it have a further quality of "inventiveness".  This is to ensure that patents are not granted (or, if they are then they are not valid) for simple variations and improvements over existing products or processes that would be obvious to people working in the relevant field.

In some jurisdictions it is common to refer to worthy inventions as being "nonobvious", while in others the terms "inventive" or "having an inventive step" are more common.  Generally, that which is obvious is not inventive, so in most cases the use of different terminology does not alter the nature of the enquiry.

Assessing obviousness involves a comparison of the invention as defined in the claims of a patent specification with a relevant body of prior art that would be readily available to a person working in the field of the invention.

See also: novelty.

Omnibus claim

An omnibus claim is a particular form of patent claim that refers to the description, drawings and/or examples of a patent specification without expressly reciting any technical features of the product or process claimed.  A typical form for an omnibus claim is "a splendiforous widget substantially as herein described with reference to the accompanying drawings."

In most jurisdictions omnibus claims are no longer considered allowable, on the basis that their scope is not sufficiently clear.  In countries (eg Australia, the UK and New Zealand) in which omnibus claims are still allowed, it is generally assumed that they are very narrow in scope, being limited to the specific embodiments of the invention (as claimed in the broadest claims) that are disclosed within the specification.  However, it must be said that court decisions on this point have been few and far between, and not entirely conclusive.

Omnibus claims are perhaps a fading relic of a past era before modern claiming practice, in which the scope of patent rights was largely to be determined from a reading of the specification as a whole, or even from the examination of a model or prototype.

Patent (monopoly)

A patent is an exclusive right, granted to the inventor by the government for a limited period (typically 20 years from filing), to deal with an invention.  A such, a patent is a form of legal monopoly.

The precise scope of the monopoly varies a little in different jurisdictions, but generally includes the exclusive right to commercial exploitation of the patented invention, eg to manufacture, use, distribute, import, export and/or sell the invention, and to authorise others to do so, ie under license.

Person Skilled in the Art

The Person Skilled in the Art (PSA) is an imaginary individual used as a benchmark for assessing whether a claimed invention is obvious or not.

In the US, the skilled person is often called the Person Having Ordinary Skill in the Art (PHOSITA).  Sometimes the term skilled addressee is used, particularly when questions arise as to how a person with relevant technical qualifications would interpret particular words or phrases appearing in the description or claims of a patent specification.

The PSA/PHOSITA is generally considered to have normal skills and knowledge in the technical field of the invention, but no particular inventive faculty.  In particular, if a claimed invention is within the grasp of the PSA/PHOSITA, then it is most probably obvious, and not patentable.

Prior art

Information that has been made available to the public before a given date is known as prior art, at that date.  Other terms that are commonly used are state of the art (esp. Europe) and background art.

The most common forms of prior art encountered during examination of patent applications are previously published patent specifications, articles from publications such as technical journals, and material made available on the Internet.  However, information made available through public use of a product or process also forms part of the prior art.

When assessing novelty and obviousness, the relevant date for determining prior art is usually the priority date of each claim.

Priority date

The priority date of a claim is the date at which the novelty and inventiveness of the claimed invention is to be assessed.  Once a patent application has been filed which describes and claims an invention, it will be apparent that any information made public after the filing date is not relevant to whether the invention was new and inventive at that time.

In appropriate circumstances, the priority date of a claim may be earlier than the date of filing of the patent application in which it appears.  For example, a patent application may be entitled to benefit from an earlier-filed application, in the same or a different country, which describes the same invention.


An application for a patent must be accompanied by a specification, which is a document that describes and defines an invention.

The description typically establishes the background to the invention before summarising the nature of the invention in broad terms, and then describing one or more specific implementations (or embodiments) which put the invention into practical use.  In most cases, one or more drawings are also provided to assist in understanding of the invention.

The precise scope of the invention to be covered by the patent monopoly is defined in one or more claims.

The specification thus consists typically of description, drawings and claims, which together must satisfy specific legal requirements.  Depending upon the particular jurisdiction in which the application is filed, these may include: written description; sufficiency; enablement; fair basis; support; and/or utility.

Sufficiency, sufficient

The term sufficiency is used in some jurisdictions to describe a requirement similar to that of enablement in the US law.  The description of the invention provided in the specification must be sufficient to enable a suitably skilled person to put the invention into effect.

See also: written description, enablementsupport, fair basis, utility.


In some jurisdictions, the patent law requires that the claims be supported by the description in the patent specification.  This terminology is used in the European Patent Convention, for example, and is understood to require a basis in the description for the subject-matter of every claim and that the scope of the claims must not be broader than is justified by the extent of the description and drawings and the contribution made by the invention.

The concept of support for the claims thus has something in common with the fair basis and/or written description requirements that exist in other jurisdictions.

See also: written description, enablementsufficiency, fair basis, utility.

Utility, usefulness

In order to be patentable an invention must be useful.  This does not mean that the use must be of any value to anyone, only that the invention defined in the claims must have some specific application, and not merely be the object of speculation or abstract interest.

Utility may also be linked to the purpose of the invention described in the patent specification.  If the invention is stated to have a particular objective, or purpose, and the claims define something that is not capable of satisfying that objective, then they may be invalid for lack of utility.

See also: written description, enablement, sufficiency, support, fair basis.

Written description

The term written description is most commonly encountered in relation to US patents, and relates to a requirement that the inventor demonstrate possession of the invention at the time of filing a patent application.

In this context, possession refers to the inventor having a complete conception of an invention along with its practical application.  The written description requirement prevents, among other things, the grant of valid patents covering general ideas for which specific practical applications have yet to be established.

In jurisdictions other than the US, the utility and/or fair basis requirements often perform a similar function.

See also: enablement, sufficiency, support, fair basis, utility.

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